U.S. patent number 11,243,644 [Application Number 16/726,530] was granted by the patent office on 2022-02-08 for touch display device and touch sensing circuit.
This patent grant is currently assigned to LG DISPLAY CO., LTD.. The grantee listed for this patent is LG Display Co., Ltd.. Invention is credited to SangHyuck Bae, Sungsu Han, HyungUk Jang, Suyun Ju, DoYoung Jung, Jongsung Kim.
United States Patent |
11,243,644 |
Ju , et al. |
February 8, 2022 |
Touch display device and touch sensing circuit
Abstract
A touch display device comprises a touch panel including a
plurality of touch electrodes; and a touch driving circuit
configured to sense one or more of the plurality of touch
electrodes, wherein the touch driving circuit has an operation
period including a plurality of touch intervals that includes a
first sensing interval and a second sensing interval, and the first
sensing interval includes at least a first time division sensing
interval and the second sensing interval includes at least a second
time division sensing interval, and wherein the touch driving
circuit is configured to detect a pen signal output from a first
pen through one or more touch electrodes of the plurality of touch
electrodes during the first time division sensing interval, and
detect a pen signal output from a second pen through one or more
touch electrodes of the plurality of touch electrodes during the
second time division sensing interval.
Inventors: |
Ju; Suyun (Gangwon-do,
KR), Jang; HyungUk (Gyeonggi-do, KR), Han;
Sungsu (Gyeonggi-do, KR), Jung; DoYoung (Seoul,
KR), Bae; SangHyuck (Seoul, KR), Kim;
Jongsung (Gyeonggi-do, KR) |
Applicant: |
Name |
City |
State |
Country |
Type |
LG Display Co., Ltd. |
Seoul |
N/A |
KR |
|
|
Assignee: |
LG DISPLAY CO., LTD. (Seoul,
KR)
|
Family
ID: |
1000006100581 |
Appl.
No.: |
16/726,530 |
Filed: |
December 24, 2019 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20200210021 A1 |
Jul 2, 2020 |
|
Foreign Application Priority Data
|
|
|
|
|
Dec 28, 2018 [KR] |
|
|
10-2018-0173152 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G06F
3/0442 (20190501); G06F 2203/04104 (20130101) |
Current International
Class: |
G06F
3/041 (20060101); G06F 3/0484 (20130101); G06F
3/0354 (20130101); G06F 3/038 (20130101); G06F
3/044 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
JP Office Action dated May 31, 2021 issued in Japanese Patent
Application No. 2019-223341 w/English Translation (10 pages). cited
by applicant.
|
Primary Examiner: Li; Lin
Attorney, Agent or Firm: Polsinelli PC
Claims
What is claimed is:
1. A touch display device comprising: a touch panel including a
plurality of touch electrodes; and a touch driving circuit
configured to sense one or more of the plurality of touch
electrodes, wherein the touch driving circuit has an operation
period including a plurality of touch intervals that includes a
first sensing interval and a second sensing interval, and the first
sensing interval includes at least a first time division sensing
interval and the second sensing interval includes at least a second
time division sensing interval, wherein the touch driving circuit
is configured to detect a first pen signal output from a first pen
through one or more touch electrodes of the plurality of touch
electrodes during the first time division sensing interval, and
detect a second pen signal output from a second pen through one or
more touch electrodes of the plurality of touch electrodes during
the second time division sensing interval, wherein the touch
driving circuit is further configured to: detect a third pen signal
output from the first pen and having a first signal frequency
through one or more touch electrodes during the first time division
sensing interval; and detect a fourth pen signal output from the
second pen and having the first signal frequency through one or
more touch electrodes during the second time division sensing
interval, wherein the first sensing interval further comprises a
third time division sensing interval, and wherein, when a third
pen, which is different from the first pen and the second pen, is
discovered, the touch driving circuit is configured to detect a
fifth pen signal output from the third pen and having a second
signal frequency, which is different from the first signal
frequency, through one or more touch electrodes during the third
time division sensing interval.
2. The touch display device of claim 1, wherein the touch driving
circuit is further configured to: detect first data from the first
pen during a first data sensing interval; and detect second data
from the second pen during a second data sensing interval.
3. The touch display device of claim 2, wherein the touch driving
circuit is configured to detect third data from the third pen
during a third data sensing interval.
4. The touch display device of claim 3, wherein the second sensing
interval further includes a fourth time division sensing interval,
wherein the touch driving circuit detects a sixth pen signal from a
fourth pen different from the first to third pens during the fourth
time division sensing interval, and wherein the first and second
sensing intervals are first and second position sensing intervals
and the first to fourth time division sensing intervals are first
to fourth time division position sensing intervals.
5. The touch display device of claim 3, wherein the second sensing
interval further includes a fourth time division sensing interval,
wherein the touch driving circuit detects a seventh pen signal
during the fourth time division sensing interval, and wherein the
first and second sensing intervals are first and second tilt
sensing intervals and the first to fourth time division sensing
intervals are first to fourth time division tilt sensing
intervals.
6. The touch display device of claim 3, wherein the second sensing
interval further includes a fourth time division sensing interval,
wherein the touch driving circuit detects an eighth pen signal
during the fourth time division sensing interval, wherein the first
and second sensing intervals include first and second position
sensing intervals and the first to fourth time division sensing
intervals include first to fourth time division position sensing
intervals, and wherein the first and second sensing intervals
further include first and second tilt sensing intervals and the
first to fourth time division sensing intervals further include
first to fourth time division tilt sensing intervals.
7. The touch display device of claim 1, further comprising: a touch
controller configured to, based on a reference touch
synchronization signal in which a first state interval defining a
touch interval and a second state interval defining a non-touch
interval are repeated, generate a touch synchronization signal in
which a first voltage level interval and a second voltage level
interval are repeated, and supply the touch synchronization signal
to the touch driving circuit, wherein one first state interval in
the reference touch synchronization signal corresponds to two or
more first voltage level intervals and one or more second voltage
level intervals.
8. The touch display device of claim 7, wherein the first sensing
interval further includes a third time division sensing interval,
and the second sensing interval further includes a fourth time
division sensing interval, and wherein one of the two or more first
voltage level intervals includes the first time division sensing
interval and the third time division sensing interval, and another
of the two or more first voltage level intervals comprises the
second time division sensing interval and the fourth time division
sensing interval.
9. The touch display device of claim 1, wherein operation modes of
the touch display device comprise: a search mode which is a default
mode and operates when no touch input by a finger and a pen is
made; a pen ID mode for receiving a pen ID when a touch input by
the pen is made; a pen mode for sensing one or more of the
position, the tilt, and data of the pen if the pen ID is received;
and a finger mode for sensing a touch by the finger if a touch
input by the finger is made, and the first sensing interval and the
second sensing interval correspond to touch intervals when the
touch driving circuit is in the pen mode.
10. The touch display device of claim 9, wherein during the search
mode, K touch intervals in one frame period comprises one or more
beacon transmission intervals, n or more finger sensing intervals,
and m pen position sensing intervals, wherein n.gtoreq.1,
m.gtoreq.1, and K.gtoreq.3, during the n or more finger sensing
intervals, a touch driving signal, the voltage level of which
swings, is applied to the plurality of touch electrodes, and during
the m pen position sensing intervals, a DC voltage is applied to
the plurality of touch electrodes.
11. The touch display device of claim 1, wherein each of the
plurality of touch intervals comprises three or more division
intervals, a pen signal comprising a plurality of pulses is applied
to one or more touch electrodes in each of the three or more
division intervals, the plurality of pulses included in the pen
signal in each of the three or more division intervals express one
symbol, and the touch driving circuit detects the pen signal based
on pen pulses during a period, except for a symbol change time
point related to position sensing.
12. A touch display device comprising: a touch panel including a
plurality of touch electrodes; and a touch driving circuit
configured to sense one or more of the plurality of touch
electrodes, wherein the touch driving circuit has an operation
period including a plurality of touch intervals that includes a
first sensing interval and a second sensing interval, and the first
sensing interval includes at least a first time division sensing
interval and the second sensing interval includes at least a second
time division sensing interval, wherein the touch driving circuit
is configured to detect a first pen signal output from a first pen
through one or more touch electrodes of the plurality of touch
electrodes during the first time division sensing interval, and
detect a second pen signal output from a second pen through one or
more touch electrodes of the plurality of touch electrodes during
the second time division sensing interval, wherein the touch
driving circuit is further configured to: detect a third pen signal
output from the first pen and having a first signal frequency
through one or more touch electrodes during the first time division
sensing interval; and detect a fourth pen signal output from the
second pen and having the first signal frequency through one or
more touch electrodes during the second time division sensing
interval, wherein the plurality of touch intervals further includes
a first data sensing interval and a second data sensing interval,
and wherein the touch driving circuit is configured to: detect a
first data output from the first pen and having the first signal
frequency through one or more touch electrodes during the first
data sensing interval; and detect a second data output from the
second pen and having the first signal frequency through one or
more touch electrodes during the second data sensing interval.
13. The touch display device of claim 12, wherein the plurality of
touch intervals further includes a third data sensing interval, and
wherein, when a third pen, which is different from the first pen
and the second pen, is discovered, the touch driving circuit is
configured to: detect a third data output from the third pen and
having a second signal frequency, which is different from the first
signal frequency, through one or more touch electrodes during the
third data sensing interval.
14. The touch display device of claim 13, wherein the plurality of
touch intervals further includes a fourth data sensing interval,
and wherein the first data sensing interval and the second data
sensing interval are included in a first frame period, and the
third data sensing interval and the fourth data sensing interval
are included in a second frame period, which is different from the
first frame period.
15. The touch display device of claim 12, wherein the first data
output from the first pen comprises a pen ID of the first pen, and
the second data output from the second pen comprises a pen ID of
the second pen.
16. The touch display device of claim 12, wherein temporal lengths
of the first and second time division sensing intervals are shorter
than those of the first and second data sensing intervals.
17. A touch display device comprising: a touch panel including a
plurality of touch electrodes; and a touch driving circuit
configured to sense one or more of the plurality of touch
electrodes, wherein the touch driving circuit has an operation
period including a plurality of touch intervals that includes a
first sensing interval and a second sensing interval, and the first
sensing interval includes at least a first time division sensing
interval and the second sensing interval includes at least a second
time division sensing interval, wherein the touch driving circuit
is configured to detect a pen signal output from a first pen
through one or more touch electrodes of the plurality of touch
electrodes during the first time division sensing interval, and
detect a pen signal output from a second pen through one or more
touch electrodes of the plurality of touch electrodes during the
second time division sensing interval, wherein the first sensing
interval further includes a third time division sensing interval,
and the second sensing interval further includes a fourth time
division sensing interval, and wherein the touch driving circuit is
configured to: detect a first signal through a first touch
electrode group of the touch panel during the first time division
sensing interval; detect a second signal through a second touch
electrode group of the touch panel during the third time division
sensing interval; detect a third signal through the first touch
electrode group of the touch panel during the second time division
sensing interval; and detect a fourth signal through the second
touch electrode group of the touch panel during the fourth time
division sensing interval.
18. The touch display device of claim 17, wherein touch electrodes
included in the first touch electrode group and touch electrodes
included in the second touch electrode group are touch electrodes
located in different areas of the touch panel.
19. The touch display device of claim 17, wherein touch electrodes
included in the first touch electrode group and touch electrodes
included in the second touch electrode group are the same touch
electrodes.
20. A touch sensing circuit comprising: a first circuit configured
to sense one or more of a plurality of touch electrodes disposed in
a touch panel and output sensing data; and a second circuit
configured to sense one or more of the position, the tilt, and
additional information of a pen based on the sensing data, wherein
an operation period of the first circuit comprises a plurality of
touch intervals, the plurality of touch intervals comprises a first
sensing interval and a second sensing interval, the first sensing
interval comprises at least a first time division sensing interval,
the second sensing interval comprises at least a second time
division sensing interval, and wherein the first circuit is
configured to: detect a first pen signal output from a first pen
through one or more touch electrodes of the plurality of touch
electrodes during the first time division sensing interval; and
detect a second pen signal output from a second pen, which is
different from the first pen, through one or more touch electrodes
of the plurality of touch electrodes during the second time
division sensing interval, wherein the first circuit is further
configured to: detect a third pen signal output from the first pen
and having a first signal frequency through one or more touch
electrodes during the first time division sensing interval; and
detect a fourth pen signal output from the second pen and having
the first signal frequency through one or more touch electrodes
during the second time division sensing interval, wherein the first
sensing interval further comprises a third time division sensing
interval, and wherein, when a third pen, which is different from
the first pen and the second pen, is discovered, the first circuit
is configured to detect a fifth pen signal output from the third
pen and having a second signal frequency, which is different from
the first signal frequency, through one or more touch electrodes
during the third time division sensing interval.
21. The touch display device of claim 20, wherein the first circuit
is configured to: detect a first data from the first pen during a
first data sensing interval; and detect a second data from the
second pen during a second data sensing interval.
Description
CROSS REFERENCE TO RELATED APPLICATION
This application claims priority from Korean Patent Application No.
10-2018-0173152, filed on Dec. 28, 2018, which is hereby
incorporated by reference in its entirety.
BACKGROUND
Field of the Disclosure
The present disclosure relates to a display device, and more
particularly, to a display device and a touch sensing circuit.
Description of the Background
As the information society develops, various requirements for touch
displays for displaying an image are increasing, and in recent
years, various display devices such as liquid crystal display
devices and organic light emitting display devices have been
utilized.
The display device has moved away from using a general input
scheme, such as buttons, a keyboard, and a mouse, and provides a
touch-based input scheme that allows the user to easily input
information and commands intuitively and conveniently.
As requirements for a touch input by a pen, in addition to a
finger, has increased, a pen touch technology also has developed.
However, there is considerable difficulty in efficiently providing
a touch by a finger and a touch by a pen together while basically
providing a display function by a touch display device.
SUMMARY
An aspect of the present disclosure is to provide a touch display
device that can effectively sense two or more pens, and a touch
sensing circuit.
Another aspect of the present disclosure is to provide a touch
display device that can perform multiplexing, by which sensing
speed may be increased, and a touch sensing circuit.
Another aspect of the present disclosure is to provide a touch
display device that can increase pen search speed, and a touch
sensing circuit.
Another aspect of the present disclosure is to provide a touch
display device that can prevent distortion of the position of a
pen, and a touch sensing circuit.
In an aspect, aspects of the present disclosure may provide a touch
display device including a touch panel including a plurality of
touch electrodes, and a touch driving circuit configured to sense
one or more of the plurality of touch electrodes.
An operation period of the touch driving circuit includes a
plurality of touch intervals. The plurality of touch intervals
includes a first sensing interval and a second sensing
interval.
The first sensing interval may include a first time division
sensing interval and a third time division sensing interval, and
the second sensing interval may include a second time division
sensing interval and a fourth time division sensing interval.
The touch driving circuit may detect a pen signal output from a
first pen through one or more touch electrodes during the first
time division sensing interval.
The touch driving circuit may detect a pen signal output from a
second pen, which is different from the first pen, through one or
more touch electrodes during the second time division sensing
interval.
The touch driving circuit may be configured to detect a signal at a
first operation frequency during the first time division sensing
interval, detect a signal at a second operation frequency, which is
different from the first operation frequency, during the third time
division sensing interval, and detect a pen signal output from the
first pen and having the first signal frequency through one or more
touch electrodes during the first time division sensing
interval.
The touch driving circuit may be configured to detect a signal at
the first operation frequency during the second time division
sensing interval, detect a signal at the second operation frequency
during the fourth time division sensing interval, and detect a pen
signal output from the second pen and having the second signal
frequency through one or more touch electrodes during the second
time division sensing interval.
The first operation frequency and the first signal frequency may be
the same.
When a third pen, which is different from the first pen and the
second pen, is discovered, the touch driving circuit may be
configured to detect a signal at a first operation frequency during
the first time division sensing interval, detect a signal at the
second operation frequency during the third time division sensing
interval, and detect a pen signal output from the third pen and
having a second signal frequency, which is different from the first
signal frequency, through one or more touch electrodes during the
third time division sensing interval. The second operation
frequency and the second signal frequency may be the same.
The first and second sensing intervals may be first and second
position sensing intervals and the first to fourth time division
sensing intervals may be first to fourth time division position
sensing intervals.
The first and second sensing intervals may be first and second tilt
sensing intervals and the first to fourth time division sensing
intervals may be first to fourth time division tilt sensing
intervals.
The plurality of touch intervals may further include a first data
sensing interval, a second data sensing interval, a third data
sensing interval, and a fourth data sensing interval.
The touch driving circuit may be configured to detect data output
from the first pen through one or more touch electrodes during a
the first data sensing interval, and may detect data output from
the second pen through one or more touch electrodes during the
second data sensing interval.
The touch driving circuit may be configured to detect data output
from the first pen and having the first signal frequency through
one or more touch electrodes by detecting data at the first
operation frequency during the first data sensing interval, and
detect data output from the second pen and having the first signal
frequency through one or more touch electrodes by detecting data at
the first operation frequency during the second data sensing
interval. The first operation frequency and the first signal
frequency may be the same.
When a third pen, which is different from the first pen and the
second pen, is discovered, the touch driving circuit may be
configured to detect data at a second operation frequency, which is
different from the first operation frequency, during the third data
sensing interval, detect data output from the third pen and having
a second signal frequency, which is different from the first signal
frequency, through one or more touch electrodes, and detect data at
the second operation frequency during the fourth data sensing
interval. The second operation frequency and the second signal
frequency may be the same.
The first data sensing interval and the second data sensing
interval may be included in a first frame period, and the third
data sensing interval and the fourth data sensing interval may be
included in a second frame period, which is different from the
first frame period.
The data output from the first pen may include a pen ID of the
first pen, and the data output from the second pen may include a
pen ID of the second pen.
The temporal lengths of the first to fourth time division sensing
intervals may be shorter than the temporal lengths of the first to
fourth data sensing intervals.
The touch driving circuit may be configured to detect a signal
through a first touch electrode group of the touch panel during the
first time division sensing interval, and detect a signal through a
second touch electrode group of the touch panel during the third
time division sensing interval.
The touch driving circuit may be configured to detect a signal
through a first touch electrode group of the touch panel during the
second time division sensing interval, and detect a signal through
a second touch electrode group of the touch panel during the fourth
time division sensing interval.
Touch electrodes included in the first touch electrode group and
touch electrodes included in the second touch electrode group may
be touch electrodes located in different areas of the touch
panel.
Touch electrodes included in the first touch electrode group and
touch electrodes included in the second touch electrode group may
be the same touch electrodes.
The touch display device may further include a touch controller
configured to, based on a reference touch synchronization signal in
which a first state interval defining a touch interval and a second
state interval defining a non-touch interval are repeated, generate
a touch synchronization signal in which a first voltage level
interval and a second voltage level interval are repeated, and
supply the touch synchronization signal to the touch driving
circuit.
One first state interval in the reference touch synchronization
signal may correspond to two or more first voltage level intervals
and one or more second voltage level intervals.
One of the two or more first voltage level intervals may include
the first time division sensing interval and the third time
division sensing interval, and another of the two or more first
voltage level intervals may include the second time division
sensing interval and the fourth time division sensing interval.
Operation modes of the touch display device may include a search
mode which is a default mode and operates when no touch input by a
finger and a pen is made, a pen ID mode for receiving a pen ID when
a touch input by the pen is made, a pen mode for sensing one or
more of the position, the tilt, and data of the pen if the pen ID
is received, and a finger mode for sensing a touch by the finger if
a touch input by the finger is made, and the first sensing interval
and the second sensing interval may correspond to touch intervals
when the touch driving circuit is in a pen mode.
During the search mode, K touch intervals in one frame period may
include one or more beacon transmission intervals, n or more finger
sensing intervals, and m pen position sensing intervals. Then,
n.gtoreq.1, m.gtoreq.1, and K.gtoreq.3.
During the n or more finger sensing intervals, a touch driving
signal, the voltage level of which swings, may be applied to the
plurality of touch electrodes, and during the m pen position
sensing intervals, a DC voltage may be applied to the plurality of
touch electrodes.
Each of the plurality of touch intervals may include three or more
division intervals, a pen signal including a plurality of pulses
may be applied to one or more touch electrodes in each of the three
or more division electrodes, and a plurality of pulses included in
a pen signal in each of the three division intervals may express
one symbol.
The touch driving circuit may detect a signal based on pen pulses
during a period, except for a symbol change time point related to
position sensing.
In another aspect, aspects of the present disclosure may provide a
touch display device including a touch panel including a plurality
of touch electrodes and configured to receive pen signals output
from two or more pens, and a touch driving circuit configured to
detect a pen signal output from the two or more pens by sensing one
or more of the plurality of touch electrodes.
The pen signals output from the two or more pens may have different
signal frequencies.
The touch driving circuit may be configured to detect a signal by
sequentially operating at two or more operation frequencies, and
detect a pen signal having the same signal frequency as an
operation frequency corresponding to a first timing through one or
more touch electrodes.
In another aspect, aspects of the present disclosure may provide a
touch sensing circuit including a first circuit (may be a touch
driving circuit) configured to sense one or more of a plurality of
touch electrodes disposed in a touch panel and output sensing data,
and a second circuit (may be a touch controller) configured to
sense one or more of the position, the tilt, and additional
information of a pen based on the sensing data.
An operation period of the first circuit may include a plurality of
touch intervals, the plurality of touch intervals may include a
first sensing interval and a second sensing interval, the first
sensing interval may include a first time division sensing interval
and a third time division sensing interval, and the second sensing
interval may include a second time division sensing interval and a
fourth time division sensing interval.
The first circuit may be configured to detect a pen signal output
from a first pen through one or more touch electrodes during the
first time division sensing interval, and detect a pen signal
output from a second pen, which is different from the first pen,
through one or more touch electrodes during the second time
division sensing interval.
The first circuit may be configured to detect a signal at a first
operation frequency during the first time division sensing
interval, detect a signal at a second operation frequency, which is
different from the first operation frequency, during the third time
division sensing interval, detect a pen signal output from the
first pen and having the first signal frequency through one or more
touch electrodes during the first time division sensing
interval.
The first circuit may be configured to detect a signal at the first
operation frequency during the second time division sensing
interval, detect a signal at the second operation frequency during
the fourth time division sensing interval, and detect a pen signal
output from the second pen and having the first signal frequency
through one or more touch electrodes during the second time
division sensing interval.
The first operation frequency and the first signal frequency may be
the same.
According to an aspect of the present disclosure, a touch display
device that can effectively sense two or more pens, and a touch
sensing circuit can be provided.
According to another aspect of the present disclosure, a touch
display device that performs multiplexing, by which sensing speed
may be increased, and a touch sensing circuit can be provided.
According to another aspect of the present disclosure, a touch
display device that can increase pen search speed, and a touch
sensing circuit can be provided.
According to another aspect of the present disclosure, a touch
display device that can prevent distortion of the position of a
pen, and a touch sensing circuit can be provided.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other aspects, features and advantages of the present
disclosure will be more apparent from the following detailed
description taken in conjunction with the accompanying drawings, in
which:
FIG. 1 is a system diagram of a touch display device according to
aspects of the present disclosure;
FIG. 2 is a view illustrating a display part of a touch display
device according to aspects of the present disclosure;
FIG. 3 is a view illustrating a touch sensing part of a touch
display device according to aspects of the present disclosure;
FIGS. 4 and 5 are views illustrating a touch driving circuit of a
touch display device according to aspects of the present
disclosure;
FIG. 6 is a diagram of time division driving timings related to
display driving and touch driving of a touch display device
according to aspects of the present disclosure;
FIGS. 7 and 8 are diagrams of simultaneous driving timings related
to display driving and touch driving of a touch display device
according to aspects of the present disclosure;
FIG. 9 is a diagram of touch driving timings of a touch display
device according to aspects of the present disclosure;
FIG. 10 is a view illustrating bidirectional communication between
a pen and a touch driving circuit for pen sensing by a touch
display device according to aspects of the present disclosure;
FIG. 11 is a view illustrating a signal applied to a touch panel
and a signal output from a pen during bidirectional communication
between the pen and the touch panel, for pen sensing by a touch
display device according to aspects of the present disclosure;
FIG. 12 is a view illustrating multi-pen sensing by a touch display
device according to aspects of the present disclosure;
FIGS. 13 to 15 are views illustrating a time division driving
scheme for multi-pen sensing by a touch display device according to
aspects of the present disclosure;
FIGS. 16 to 20 are views illustrating a time
division/multi-frequency driving scheme for multi-pen sensing by a
touch display device according to aspects of the present
disclosure;
FIG. 21 is a view illustrating multiplexing driving schemes of a
touch display device according to aspects of the present
disclosure;
FIG. 22 is a view illustrating fast pairing of a touch display
device according to aspects of the present disclosure;
FIG. 23 is a view illustrating a driving method for enhancing a
touch/pen report rate of a touch display device according to
aspects of the present disclosure;
FIG. 24 is a view illustrating an issue of losing a position of a
pen when the pen is sensed by a touch display device according to
aspects of the present disclosure;
FIG. 25 is a view illustrating the degrees of transition for
operation modes of a touch display device according to aspects of
the present disclosure;
FIG. 26 is a flowchart illustrating transition methods for
operation modes of a touch display device according to aspects of
the present disclosure;
FIG. 27 is a diagram of driving timings for operation modes of a
touch display device according to aspects of the present
disclosure;
FIG. 28 is a view illustrating a sensitivity decreasing issue when
a pen is sensed by a touch display device according to aspects of
the present disclosure;
FIG. 29 is a view illustrating a sensitivity enhancing method when
a pen is sensed by a touch display device according to aspects of
the present disclosure; and
FIGS. 30 and 31 are views illustrating a control method for
enhancing sensitivity when a pen is sensed by a touch display
device according to aspects of the present disclosure.
DETAILED DESCRIPTION
Hereinafter, some aspects of the present disclosure will be
described in detail with reference to the accompanying illustrative
drawings. In designating elements of the drawings by reference
numerals, the same elements will be designated by the same
reference numerals although they are shown in different drawings.
Further, in the following description of the present disclosure, a
detailed description of known functions and configurations
incorporated herein will be omitted when it may make the subject
matter of the present disclosure rather unclear.
In addition, terms, such as first, second, A, B, (a), (b) or the
like may be used herein when describing components of the present
disclosure. Each of these terminologies is not used to define an
essence, order or sequence of a corresponding component but used
merely to distinguish the corresponding component from other
component(s). In the case that it is described that a certain
structural element "is connected to", "is coupled to", or "is in
contact with" another structural element, it should be interpreted
that another structural element may "be connected to", "be coupled
to", or "be in contact with" the structural elements as well as
that the certain structural element is directly connected to or is
in direct contact with another structural element.
FIG. 1 is a system diagram of a touch display device 100 according
to aspects of the present disclosure. FIG. 2 is a view illustrating
a display part of a touch display device 100 according to aspects
of the present disclosure. FIG. 3 is a view illustrating a touch
sensing part of a touch display device 100 according to aspects of
the present disclosure;
Referring to FIG. 1, the touch display device 100 according to the
aspects of the present disclosure may provide a display function of
displaying an image. In addition, the touch display device 100
according to aspects of the present disclosure may provide a touch
sensing function of sensing a touch of a finger of a user and/or a
pen, and a touch input function of performing input processing
according to the touch of the finger of the user and/or the pen by
using a touch sensing result.
Referring to FIGS. 1 and 2, the touch display device 100 according
to the aspects of the present disclosure, in order to provide a
display function, may include a display panel DISP in which a
plurality of data lines DL and a plurality of gate lines GL may be
disposed, and a plurality of sub-pixels SP defined by the plurality
of data lines DL and the plurality of gate lines GL are arranged,
and display driving circuits for driving the display panel
DISP.
Referring to FIGS. 1 and 2, each of the display driving circuits
may include a data driving circuit DDC that drives a plurality of
data lines DL, a gate driving circuit GDC that drives a plurality
of gate lines GL, and a display controller DCTR that controls the
data driving circuit DDC and the gate driving circuit GDC.
Referring to FIGS. 1 and 3, the touch display device 100 according
to the aspects of the present disclosure may include a touch panel
TSP in which a plurality of touch electrodes TE are disposed to
provide a touch sensing function, a touch driving circuit TDC that
drives and senses the touch panel TSP, and a touch controller TCTR
that detects (senses) whether there is a touch by a pointer of the
user and/or a touch position by using touch sensing data
corresponding a sensing result of the touch driving circuit TDC.
The structure including the touch driving circuit TDC and the touch
controller TCTR may be called a touch sensing circuit.
The pointer of the user may be a finger or a pen.
The pen may be a passive pen having no signal
transmission/reception function or an active pen having a signal
transmission/reception function.
Referring to FIG. 2, a plurality of data lines DL disposed in a row
direction (or a column direction) and a plurality of gate lines GL
disposed in a column direction (or a row direction) may be disposed
in the display panel DISP.
Referring to FIG. 3, a plurality of touch electrodes TE, and a
plurality of touch lines TL for electrically connecting the
plurality of touch electrodes TE and the touch driving circuit TDC
may be disposed in the touch panel TSP.
The touch driving circuit TDC may apply a touch driving signal TD
to all or some of the plurality of touch electrodes TE, and may
sequentially sense all or some of the plurality of touch electrodes
TE.
As an example, the plurality of touch electrodes TE may be arranged
in a matrix form.
The plurality of touch electrodes TE may be in various forms. For
example, one touch electrode TE may be a plate-shaped electrode
having no opening, or may be an electrode in a mesh form having
openings, and may be an electrode in a form having several bending
parts.
When the touch electrode TE is a plate-shaped electrode, it may be
a transparent electrode. When the touch electrode TE is an
electrode in a mesh form or an electrode having a bent form, it may
be an opaque electrode.
The touch panel TSP may be present outside the display panel DISP,
and may be embedded in the display panel DISP. In the following,
for convenience of description, it will be assumed that the touch
panel TSP is embedded in the display panel DISP.
Each of the plurality of touch electrodes TE may be superimposed
with two or more sub-pixels SP.
As an example, the plurality of touch lines TL may be disposed
parallel to a plurality of data lines DL.
A touch driving circuit TDC for driving the plurality of touch
electrodes TE may be further included.
The touch driving circuit TDC may supply a common voltage VCOM to
the plurality of touch electrodes TE through a plurality of touch
lines TL.
The display controller DCTR controls the data driving circuit DDC
and the gate driving circuit GDC by supplying various control
signals DCS and GCS to the data driving circuit DDC and the gate
driving circuit GDC.
The display controller DCTR starts scanning according to times
implemented in respective frames, converts input image data input
from the outside according to a data signal format used in the data
driving circuit DDC, outputs the converted digital image data DATA,
and controls data driving at a suitable time according to the
scanning.
The gate driving circuit GDC sequentially supplies gate signals of
an on voltage or an off voltage to the plurality of gate lines GL
according to a control of the display controller DCTR.
If a specific gate line GL is opened by the gate driving circuit
GDC, the data driving circuit DDC converts the image data signal
received from the display controller DCTR to an image analog
signal, and supplies a data signal VDATA corresponding to the image
analog signal to the plurality of data lines DL.
The display controller DCTR may be a timing controller used in a
general display technology, may be a control device including the
timing controller, which further performs other control functions,
or may be a control device that is different from the timing
controller.
The display controller DCTR may be implemented by a separate
component from the data driving circuit DDC, and may be implemented
by an integrated circuit together with the data driving circuit
DDC.
The data driving circuit DDC drives the plurality of data lines DL
by supplying data signals VDATA to the plurality of data lines DL.
The data driving circuit DDC also may be called `a source
driver`.
The data driving circuit DDC may include at least one source driver
integrated circuit SDIC. Each source driver integrated circuit SDIC
may include a shift register, a latch circuit, a digital-analog
converter DAC, and an output buffer circuit. Each source driver
integrated circuit SDIC may further include an analog to digital
converter ADC according occasions.
Each source driver integrated circuit SDIC may be a bonding pad of
the display panel DISP in a tape automated bonding scheme or a chip
on glass scheme, may be directly disposed in the display panel
DISP, and may be integrated and disposed in the display panel DISP
according to occasion. Each source driver integrated circuit SDIC
may be implemented in a chip on film COF scheme mounted on a film
connected to the display panel DISP.
The gate driving circuit GDC sequentially drives the plurality of
gate lines GL by sequentially supplying gate signals VGATE (also
called a scan voltage, a scan sigal, or a gate voltage) to the
plurality of gate lines. The gate driving circuit GDC also may be
called `a scan driver`.
The gate signals VGATE include off-level gate voltages, by which
the corresponding gate lines GL are closed, and on-level gate
voltages, by which the corresponding gate lines GL are opened.
In more detail, the gate signals VGATE include off-level gate
voltages, by which the transistors connected to the corresponding
gate lines GL are turned off, and on-level gate voltages, by which
the transistors connected to the corresponding gate lines GL are
turned on.
When the transistors are of N type, the off-level gate voltages are
low-level gate voltages VGL and the on-level gate voltages are
high-level gate voltages VGH. When the transistors are of P type,
the off-level gate voltages are high-level gate voltages VGL and
the on-level gate voltages are low-level gate voltages VGH. In the
following, for convenience of description, it will be exemplified
that the off-level gate voltages are low-level gate voltages VGL
and the on-level gate voltages are high-level gate voltages
VGH.
The gate driving circuit GDC may include at least one gate driver
integrated circuit GDIC. Each gate driver integrated circuit GDIC
may include a shift register and a level shifter.
Each gate driver integrated circuit GDIC may be a bonding pad of
the display panel DISP in a tape automated bonding scheme TAB or a
chip on glass scheme COG, may implemented in a gate in panel type
GIP to be directly disposed in the display panel DISP, and may be
integrated and disposed in the display panel DISP according to
occasion. Each gate driver integrated circuit GDIC may be
implemented in a chip on film COF scheme mounted on a film
connected to the display panel DISP.
As in FIG. 1, the data driving circuit DDC may be located on one
side (e.g., the upper side or the lower side) of the display panel
DISP, and according to occasion, may be located both sides (e.g.,
the upper side and the lower side) of the display panel DISP
depending on a driving scheme or a panel design scheme.
As in FIG. 1, the gate driving circuit GDC may be located on one
side (e.g., the left side or the right side) of the display panel
DISP, and according to occasion, may be located both sides (e.g.,
the left side and the right side) of the display panel DISP
depending on a driving scheme or a panel design scheme.
The touch display device 100 according to the aspects may be
display devices of various types, such as a liquid crystal display
device and an organic light emitting display device. The display
panel DISP according to the aspects may be display panels of
various types, such as a liquid crystal display panel and an
organic light emitting display panel.
Each sub-pixel SP disposed in the display panel DISP may include
one or more circuit elements (e.g., a transistor and a
capacitor).
For example, when the display panel DISP is a liquid crystal
display panel, a pixel electrode PXL may be disposed in each
sub-pixel SP, and a transistor TR may be electrically connected
between the pixel electrode PXL and the data line DL. The
transistor TR may be turned on by a gate signal VGATE supplied to a
gate node through a gate line, and when being turned on, may apply
a data signal VDATA to a pixel electrode PXL electrically connected
to a drain node (or a source node) by outputting a data signal
VDATA supplied to a source node (or a drain node) to the drain node
(or the source node) through a data line DL. An electric field is
generated between a pixel electrode PXL, to which the data signal
VDATA is applied, and a common electrode, to which a common voltage
VCOM is applied, and a capacitance is generated between the pixel
electrode PXL and the common electrode.
The structure of each sub-pixel SP may be variously determined
according to a panel type, a provision function, a design scheme,
and the like.
The plurality of touch electrodes TE mentioned above correspond to
a touch sensor, to which a touch driving signal TDS is applied when
touch driving is performed by the touch driving circuit TDC, and
which may be sensed by the touch driving circuit TDC.
The plurality of touch electrodes TE may be display driving
electrodes, to which a data signal VDATA and a common voltage VCOM
that generates an electric field when the display are driven, is
applied.
Accordingly, when the touch driving is performed, a touch driving
signal TDS may be applied to the touch electrodes TE, and when the
display driving is performed, the common voltage VCOM may be
applied to the touch electrodes TE.
When the display driving and the touch driving are performed at
different timings, the touch electrodes TE function as the display
driving electrodes during the display driving, and the touch
electrodes TE function as a touch sensor during the touch
driving.
As will be described below, if the display driving and the touch
driving are simultaneously performed, the touch electrodes TE
function as both the display driving electrodes and the touch
sensor during a simultaneous driving period in which the display
driving and the touch driving are simultaneously performed.
Referring to FIGS. 2 and 3, in a first touch electrode and a second
touch electrode, among the plurality of touch electrodes, disposed
in the same row, two or more data lines DL superimposed on the
first touch electrode may be superimposed on the second touch
electrode in the same way. However, two or more gate lines GL
superimposed on the first touch electrode are not superimposed on
the second touch electrode.
The plurality of touch lines TL include a first touch line for
electrically connecting the first touch electrode and the touch
driving circuit TDC, and a second touch line for electrically
connecting the second touch electrode and the touch driving circuit
TDC.
The first touch line and the second touch line are insulated from
each other in the touch panel TSP. According to occasion, the first
touch line and the second touch line may be electrically connected
to each other in the touch driving circuit TDC.
The first touch line may be superimposed on the second touch
electrode, and may be insulated from the second touch electrode in
the touch panel TSP.
The touch controller TCTR, for example, may be implemented by a
micro control unit (MCU), and a processor.
The display controller DCTR and the touch controller TCTR may be
implemented separately or may be integrated to be implemented.
The touch display device 100 according to the aspects of the
present disclosure may sense a touch based on a self-capacitance of
the touch electrode TE, or may sense a touch based on a
mutual-capacitance between the touch electrodes TE.
When the touch display device 100 according to the aspects of the
present disclosure senses a touch based on the self-capacitance,
the touch driving circuit TDC may supply a touch driving signal TDS
in a form of a signal having a variable voltage level to one or
more of the plurality of touch electrodes TE, may sense a touch
sensing signal from the touch electrodes TE, to which, the touch
driving signal is applied, and output sensing data, and the touch
controller TCTR may calculate whether there is a touch and/or a
touch position by using the sensing data.
When the touch display device 100 according to the aspects of the
present disclosure senses a touch based on the mutual-capacitance,
the touch driving circuit TDC may supply a touch driving signal TDS
to, among the plurality of touch electrodes TE, a touch electrode
functioning as a driving electrode, may sense a touch sensing
signal from, among the pluralit of the touch electrodes TE, another
touch electrode functioning as a sensing electrode, and output
sensing data, and the touch controller TCTR may calculate whether
there is a touch and/or a touch position by using the sensing
data.
In the following, for convenience of description, it will be
assumed that the touch display device 100 according to the aspects
of the present disclosure senses a touch based on a
self-capacitance.
The touch driving signal TDS output from the touch driving circuit
TDC may be a signal having a predetermined voltage level, and may
be a signal having a variable voltage level.
When the touch driving signal TDS is a signal having a variable
voltage level, the touch driving signal TDS, for example, may be
various signal waves, such as a sinusoidal wave form, a triangular
wave form, or a spherical wave form.
The data driving circuit DDC may convert digital image data DATA
received from the display controller DCTR to a data signal VDATA in
the form of an analog voltage, through a digital-to-analog
converter (DAC).
During a digital-to-analog conversion, the data driving circuit DDC
may convert digital image data DATA to a data signal in the form of
an analog voltage based on a plurality of gamma reference voltage
GRV.
A plurality of gamma reference voltages are supplied from a gamma
circuit GAM. The gamma circuit GAM may be present outside or inside
the data driving circuit DDC.
A ground voltage GND may be applied to the display panel DISP. The
ground voltage GND may be a DC voltage and may be an AC voltage
having a variable voltage level.
In the following, for convenience of description, it will be
assumed that the touch panel TSP is embedded in the display panel
DISP.
FIG. 4 is a view illustrating a touch driving circuit TDC of a
touch display device 100 according to aspects of the present
disclosure. FIG. 5 is a view illustrating a touch driving operation
for a one touch electrode row performed by a touch driving circuit
TDC of a touch display device TDC according to aspects of the
present disclosure.
Referring to FIG. 4, the touch driving circuit TDC according to the
aspects of the present disclosure may include a first multiplexer
circuit MUX1, a sensing unit block SUB including a plurality of
sensing units SU, a second multiplexer circuit MUX2, and an
analog-to-digital converter ADC.
The first multiplexer circuit MUX 1 may include one or more
multiplexers. The second multiplexer circuit MUX 2 may include one
or more multiplexers.
Referring to FIG. 4, each sensing unit SU may include a
pre-amplifier Pre-AMP, an integrator INTG, and a sample-and-hold
circuit SHA.
One pre-amplifier Pre-AMP may be electrically connected to one or
more touch electrodes TE.
For example, as illustrated in FIG. 5, one pre-amplifier Pre-AMP
may be electrically connected to several touch electrodes TE1, TE2,
TE3, TE4, TE5, . . . included in one touch electrode column TE
Column.
Referring to FIG. 5, one pre-amplifier Pre-AMP may supply a touch
driving signal TDS to, among one or more touch electrodes TE1, TE2,
TE3, TE4, TE5, . . . that may be connected, one sensing target
touch electrode (e.g., TE1) selected as a sensing target by turns,
and may receive and detect a sensing signal from the sensing target
touch electrode (e.g., TE1), to which a driving signal TDS is
applied.
In more detail, referring to FIG. 5, the first multiplexer circuit
MUX1 connects, among several touch electrodes TE1, TE2, TE3, TE4,
TE5, . . . included in a touch electrode column, a sensing target
touch electrode TE1 that is a touch electrode selected as a sensing
target to the pre-amplifier Pre-AMP.
That is, the first multiplexer MUX1 connects node b connected to
the pre-amplifier Pre-AMP to node a1 connected to the selected
sensing target touch electrode TE1.
Accordingly, the pre-amplifier Pre-AMP receives a touch driving
signal TDS output from a touch power circuit TPIC through a first
input terminal I1, and outputs the touch driving signal TDS to a
second input terminal I2. The first input terminal I1 may be a
non-reverse input terminal, and the second input terminal I2 may be
a reverse input terminal.
The touch driving signal TDS output from the second input terminal
I2 of the pre-amplifier Pre-AMP is supplied to the sensing target
touch electrode TE1 selected by the first multiplexer MUX1.
The first multiplexer MUX1 connects nodes a2, a3, a4, a5, . . .
connected to, among several touch electrodes TE1, TE2, TE3, TE4,
TE5, . . . included in the corresponding touch electrode column,
the remaining non-sensing target touch electrodes TE2, TE3, TE4,
TE5, . . . except for the sensing target touch electrode TE1 to
node C directly connected to the touch power circuit TPIC in
common.
Accordingly, among several touch electrodes TE1, TE2, TE3, TE4,
TE5, . . . included in the touch electrode column, the non-sensing
target touch electrodes TE2, TE3, TE4, TER5, . . . may be supplied
with a load free driving signal LFDS corresponding to the touch
driving signal TDS while not passing through the pre-amplifier
Pre-AMP. The load free driving signal LFDS may be the same signal
as the touch driving signal TDS or may be a signal, at least one of
the frequency, the phase, and the amplitude of which corresponds to
that of the touch driving signal TDS. This will be described again
in the following.
Thereafter, the pre-amplifier Pre-AMP may receive a sensing signal
from the sensing target touch electrode TE1. A feedback capacitor
Cfb is charged by the sensing signal received in this way, and
accordingly, the signal output to the output terminal O of the
pre-amplifier Pre-AMP may be input to the integrator INTG.
The pre-amplifier Pre-AMP and the integrator INTG may be integrated
to be implemented.
The integrator INTG integrates signals output from the
pre-amplifier Pre-AMP. As in FIG. 31, the integrator INTG may
include an operation amplifier OP-AMP, and a capacitor C connected
between a reverse input terminal and an output terminal of the
operation amplifier OP-AMP.
The analog-to-digital converter ADC may output, toward the touch
controller TCTR, touch sensing data obtained by converting the
integration value output to the integrator INTG into a digital
value.
The touch controller TCTR may detect whether there is a touch input
by a finger and/or a pen, and/or a touch position, based on the
touch sensing data.
FIG. 6 is a diagram of time division driving timings related to
display driving and touch driving of a touch display device 100
according to aspects of the present disclosure.
Referring to FIG. 6, the touch display device 100 according to the
aspects of the present disclosure may perform display driving and
touch driving in a time division interval. The driving scheme is
called time division driving.
During a display driving period, a common voltage VCOM in the form
of a DC voltage is applied to a plurality of touch electrodes TE.
Gate signals VGATE1 and VGATE2 having a turn-on level voltage VGH
at a scanning time after having a state of a turn-off level voltage
VGL may be sequentially applied to a plurality of gate lines GL1
and GL2. Corresponding data signals VDATA may be applied to a
plurality of data lines DL.
During a touch driving period after the display driving period, a
touch driving signal TDS, the voltage level of which varies over
time, may be applied to all or some of the plurality of touch
electrodes TE.
During the touch driving period, when a touch driving signal TDS is
applied to the touch electrode TE that is a touch sensing target, a
signal that is the same as or corresponds to the touch driving
signal TDS may be applied to the touch electrode TE that is a
non-sensing target disposed in the display panel DISP, the data
lines DL, and the gate lines G. This is called load free driving
(LFD). The LFD can prevent an unnecessary parasitic capacitance,
and can prevent deterioration of touch sensitivity due to the
parasitic capacitance.
During the touch driving period, in order to prevent a parasitic
capacitance between the touch electrode TE that is a sensing target
and another touch electrode TE, an LFD sigal that is the same as or
corresponds to the touch driving signal TDS applied to the touch
electrode TE that is a sensing target may be applied to all or some
of the plurality of touch electrodes TE disposed in the display
panel DISP.
During the touch driving period, in order to prevent a parasitic
capacitance between the touch electrode TE and the data lines DL,
an LFD signal D_LFDS that is the same as or corresponds to the
touch driving signal TDS applied to the touch electrode TE that is
a sensing target may be applied to all or some of the plurality of
data lines DL disposed in the display panel DISP.
During the touch driving period, in order to prevent a parasitic
capacitance between the touch electrode TE and the gate lines GL,
an LFD signal G_LFDS that is the same as or corresponds to the
touch driving signal TDS applied to the touch electrode TE that is
a sensing target may be applied to all or some of the plurality of
gate lines GL disposed in the display panel DISP.
During the touch driving period, the frequencies and the phases of
the LFD signals applied to the touch electrode TE that is a
non-sensing target disposed in the display panel DISP, the data
lines DL, and the gate lines GL may correspond to the frequency and
the phase of the touch driving signal TDS applied to the touch
electrode TE that is a sensing target.
During the touch driving period, the amplitudes of the LFD signals
applied to the touch electrode TE that is a non-sensing target
disposed in the display panel DISP, the data lines DL, and the gate
lines GL may correspond to the amplitude of the touch driving
signal TDS applied to the touch electrode TE that is a sensing
target.
FIGS. 7 and 8 are diagrams of simultaneous driving timings related
to display driving and touch driving of a touch display device 100
according to aspects of the present disclosure.
Referring to FIGS. 7 and 8, the touch display device 100 according
to the aspects of the present disclosure may simultaneously perform
display driving and touch driving. The driving scheme is called
simultaneous driving.
Referring to FIGS. 7 and 8, while a data signal VDATA for
displaying an image is supplied to the plurality of data lines DL
such that the display driving is performed, the touch driving
circuit TDC may supply a touch driving signal TDS that swings with
a predetermined amplitude .DELTA.V to the plurality of touch
electrodes TE.
The touch driving signal TDS may be a signal, the voltage level of
which swings (changes). The touch driving signal TDS is also called
a modulation signal, an AC signal, or a pulse signal.
Referring to FIG. 7, the width W of a high level voltage period of
the touch driving signal TDS may be shorter than one horizontal
period 1H for the display driving.
During a high level voltage period of a data signal VDATA for
displaying an image, which is supplied to, among the plurality of
data lines DL, at least one data line DL, or during a high level
voltage period of a gate signal VGATE1 and VGATE2, which is
supplied to, among the plurality of gate lines GL, at least one
gate line GL, the voltage level of the touch driving signal TDS may
change one or more times.
Referring to FIG. 8, the width W of a high level voltage period of
the touch driving signal TDS may be longer than one horizontal
period 1H for the display driving.
During the high level voltage period of the touch driving signal
TDS, the voltage level of a data signal VDATA for displaying an
image supplied to, among the plurality of data lines DL, at least
one data line DL may be changed one or more times, or the voltage
level of a gate signal VDATA for displaying an image supplied to,
among the plurality of gate lines DL, at least one gate line DL may
be changed one or more times.
Referring to FIGS. 7 and 8, during the simultaneous driving, a data
signal VDATA applied to a data line DL has a form in which an
original signal part for displaying an image and the touch driving
signal TDS are combined with each other. Accordingly, a point of a
voltage change that is the same as the amplitude .DELTA.V of the
touch driving signal TDS may be present in the data signal
VDATA.
Referring to FIGS. 7 and 8, during the simultaneous driving, a gate
signal VGATE1, VGATE2, VGATE3, and VGATE4 applied to a gate line DL
has a form in which an original signal part for driving a gate and
the touch driving signal TDS are combined with each other.
Accordingly, a point of a voltage change that is the same as the
amplitude .DELTA.V of the touch driving signal TDS may be present
in the gate signal VGATE1, VGATE2, VGATE3, and VGATE4.
As described above, because the data signal VDATA has a point of a
voltage change that is the same as the amplitude .DELTA.V of the
touch driving signal TDS, by removing a part of the data signal
VDATA corresponding to the touch driving signal TDS, the data
signal VDTA comes into the same state as the data signal VDATA of
the display driving period during the time division driving.
Similarly, because the gate signal VGATE1, VGATE2, VGATE3, and
VGATE4 has a point of a voltage change that is the same as the
amplitude .DELTA.V of the touch driving signal TDS, by removing a
part of the gate signal VGATE corresponding to the touch driving
signal TDS, the gate signal VGATE comes into the same state as the
gate signal VGATE of the display driving period during the time
division driving.
The feature that the data signal VDATA has a point of the same
voltage change as the amplitude .DELTA.V of the touch driving
signal TDS and the gate signal VGATE has a point of the same
voltage change as the amplitude .DELTA.V of the touch driving
signal TDS may mean that the data signal VDATA and the gate signal
VGATE are modulated with reference to the touch driving signal
TDS.
As described above, when signal waveforms of the data signal VDATA
and the gate signal VGATE are changed (modulated), the display
driving may not be influenced by the touch driving even though the
display driving and the touch driving are simultaneously performed
during the simultaneous driving.
The feature that the signal waveforms of the data signal VDATA and
the gate signal VGATE are changed corresponds to a kind of LFD
driving that improves touch sensitivity by preventing an
unnecessary parasitic capacitance.
For example, the simultaneous driving may be performed through a
modulation technique or a ground modulation technique.
In the case of a gamma modulation technique, the data signal VDATA
may be changed by performing digital-to-analog conversion
processing by using a gamma reference voltage GRV, the frequency,
the phase, and the width .DELTA.V of which correspond to those of
the touch driving signal TDS when the data driving circuit DDC is
digital-to-analog converted.
The above-described gate signal VGATE may be generated by changing
a turn-off level voltage VGL and a turn-on level voltage VGH that
are necessary for generating the gate signal such that the
frequencies, the phases, and the amplitudes .DELTA.V correspond to
those of the touch driving signal TDS.
The ground modulation technique is a scheme in which the ground
voltage GND applied to the display panel DISP is a signal having a
variable voltage level, and all kinds of signals applied to the
display panel DISP are swung with reference to the ground voltage
GND by allowing the frequencies and the phases of the signals to
correspond to the frequency and the phase of the touch driving
signal TDS.
The touch display device 100 according to the aspects of the
present disclosure may perform the time division driving at any
timing after performing the simultaneous driving.
FIG. 9 is a diagram of touch driving timings of a touch display
device 100 according to aspects of the present disclosure.
Referring to FIG. 9, the touch display device 100 according to the
aspects of the present disclosure may time-divide a frame for
sensing all the touch electrodes TE disposed in the touch panel TSP
into a plurality of touch intervals LHB 1 to LHB 16, and may sense
the touch electrodes TE corresponding to the plurality of touch
intervals LHB 1 to LHB 16. In the following, for convenience of
description, it will be assumed that one frame period is
time-divided into 16 touch intervals LHB 1 to LHB 16.
Referring to FIG. 9, the touch driving circuit TDC may recognize
the plurality of touch intervals LHB 1 to LHB 16 through a touch
synchronization signal Tsync.
The touch synchronization signal Tsync is a control signal in which
touch level intervals defining timings of the plurality of touch
intervals LHB 1 to LHB 16 and non-touch level intervals that define
non-touch intervals that are not the plurality of touch intervals
LHB 1 to LHB 16 are included.
For example, as illustrated in FIG. 9, the touch level intervals
may be low level voltage intervals and the non-touch level
intervals may be high level voltage intervals. Unlike this, the
touch level intervals may be high level voltage intervals and the
non-touch level intervals may be low level voltage intervals.
In the time division driving scheme performed while the display
driving and the touch driving are time-divided, the non-touch level
intervals may be the display driving intervals. In the simultaneous
driving scheme in which the display driving and the touch driving
are simultaneously performed, the non-touch level intervals may be
intermissions between the touch level intervals.
FIG. 10 is a view illustrating bidirectional communication between
a pen and a touch driving circuit TDC for pen sensing by a touch
display device 100 according to aspects of the present
disclosure.
Referring to FIG. 10, the touch display device 100 according to the
aspects of the present disclosure may perform bidirectional
communication between the pen and the touch driving circuit TDC by
the medium of the touch panel TSP for pen sensing.
Referring to FIG. 10, the bidirectional communication may include
uplink communication through which the touch driving circuit TDC
transmits an uplink signal ULS to the pen through the touch panel
TSP, and downlink communication through which the pen transmits a
downlink signal DLS to the touch driving circuit through the touch
panel TSP.
During the uplink communication, the pen may receive an uplink
signal ULS through one or more touch electrodes TE by applying, by
the touch driving circuit TDC, an uplink signal ULS to one or more
touch electrodes TE disposed in the touch panel TSP.
During the downlink communication, the touch driving circuit TDC
may receive a downlink signal DLS through one or more touch
electrodes TE by applying, by the pen, a downlink signal DLS to one
or more touch electrodes TE disposed in the touch panel TSP.
FIG. 11 is a view illustrating a signal applied to a touch panel
TSP and a signal output from a pen during bidirectional
communication between the pen and the touch panel TSP, for pen
sensing by a touch display device 100 according to aspects of the
present disclosure.
FIG. 12 is a view illustrating multi-pen sensing by a touch display
device 100 according to aspects of the present disclosure.
Referring to FIG. 12, the touch display device 100 according to the
aspects of the present disclosure may perform both sensing of a
touch input by the finger (finger sensing) and sensing of a touch
input by the pen (pen sensing).
Accordingly, the plurality of touch intervals LHB 1 to LHB 16 may
include one finger sensing interval F and pen sensing intervals. In
the specification, the sensing intervals are used as the same
meaning as the touch intervals.
Referring to FIG. 11, for example, among the plurality of touch
intervals LHB 1 to LHB 16, the pen sensing intervals may include
one or more position sensing intervals P for sensing the position
of the pen, one or more tilt sensing intervals T for sensing the
tilt of the pen, and one or more data sensing intervals D for
sensing the data of the pen.
Referring to FIG. 11, for example, among the plurality of touch
intervals LHB 1 to LHB 16, the pen sensing intervals may further
include one or more beacon transmission intervals B for
transmitting a beacon signal BCON for controlling driving of the
pen to the pen.
It may be defined as a protocol to which kind of touch interval LHB
the plurality of touch intervals LHB 1 to LHB 16 in one frame
period is assigned.
According to a modification of the protocol, the plurality of touch
intervals LHB 1 to LHB 16 in one frame period may include some of a
finger sensing interval F, a beacon transmission interval B, a
position sensing interval P, a tilt sensing interval T, and a data
sensing interval D. Specially, the plurality of touch intervals LHB
1 to LHB 16 in one frame period may include one or more of a
position sensing interval P, a tilt sensing interval T, and a data
sensing interval D.
Referring to FIG. 11, during the beacon transmission interval B,
the touch driving circuit TDC may apply a beacon signal BCON to all
or some of the plurality of touch electrodes TE disposed in the
touch panel TSP. Accordingly, the pen may receive a beacon signal
BCON applied to the touch panel TSP.
The beacon signal BCON is a kind of an uplink signal ULS, and is a
signal for transmitting various pieces of information that define a
driving protocol.
The beacon signal BCON may include the same information during
every transmission, and may include different pieces of
information.
The beacon signal BCON, for example, may include touch panel
information (may be display panel information when the touch panel
TSP is embedded in the display panel DISP) such as touch panel
identification information and touch panel type information (e.g.,
an in-cell type), and may include touch interval LHB information,
multiplexer driving information, power mode information (e.g., LHB
information that does not drive the panel and the pen for saving
power consumption), and error check information.
The beacon signal BCON may include information for driving timing
synchronization between the touch panel TSP and the pen.
The beacon signal BCON may include identification information ID of
the pen used during the communication with the touch driving
circuit TDC. The identification information ID of the pen may be
identification information given to the pen by the pen
manufacturer, and may be identification information temporarily
given to the pen during a period in which communication may be made
between the pen and the touch display device 100 after the touch
display device 100 discovers the pen.
The beacon signal BCON may include a pen signal PENS output by the
pen and/or frequency information of data.
The beacon signal BCON may include information on a pen signal PENS
output by the pen and/or a signal format (a pulse state and a pulse
format) of data.
Various pieces of information included in the above-described
beacon signal BCON may be stored in a lookup table of the touch
display device 100, and an update history may be transmitted to the
pen during updating. The lookup table may be shared with the pen in
advance.
Referring to FIG. 11, during the position sensing interval P and
the tilt sensing interval T, the touch driving circuit TDC may
apply a DC voltage to all or some of the plurality of touch
electrodes TE disposed in the touch panel TSP. During the position
sensing interval P and the tilt sensing interval T, the DC voltage
applied to the touch electrodes TE may be regarded as a kind of an
uplink signal ULS.
Unlike this, during the position sensing interval P and the tilt
sensing interval T, the touch driving circuit TDC may apply a
modulation signal (also called an AC signal or a pulse signal)
having a variable voltage level to all or some of the plurality of
touch electrodes TE disposed in the touch panel TSP. During the
position sensing interval P and the tilt sensing interval T, the
modulation signal applied to the touch electrodes TE may be
regarded as a kind of an uplink signal ULS.
Referring to FIG. 11, during the position sensing interval P and
the tilt sensing interval T, the pen outputs a pen signal PENS if
the touch driving circuit TDC applies a DC voltage (or a modulation
signal) to the touch panel TSP.
The pen signal PENS output from the pen is a kind of a downlink
signal DLS, and may be applied to one or more touch electrodes TE
disposed in the touch panel TSP.
The touch driving circuit TDC may receive a pen signal PENS output
from the pen and applied to the touch panel TSP through one or more
touch electrodes TE.
Referring to FIG. 11, during the data sensing interval D, the touch
driving circuit TDC may apply a DC voltage to all or some of the
plurality of touch electrodes TE disposed in the touch panel TSP.
During the data sensing interval D, the DC voltage applied to the
touch electrodes TE may be regarded as a kind of an uplink signal
ULS.
Unlike this, during the position sensing interval P and the tilt
sensing interval T, the touch driving circuit TDC may apply a
modulation signal (also called an AC signal or a pulse signal)
having a variable voltage level to all or some of the plurality of
touch electrodes TE disposed in the touch panel TSP. During the
data sensing interval D, the modulation signal applied to the touch
electrodes TE may be regarded as a kind of an uplink signal
ULS.
Referring to FIG. 11, during the data sensing interval D, the pen
outputs data DATA if the touch driving circuit TDC applies a DC
voltage (or a modulation signal) to the touch panel TSP.
The data output from the pen may include various pieces of
additional information of the pen as a kind of a downlink signal
DLS. The various pieces of additional information of the pen, for
example, may include one or more of pressure information (writing
pressure information) and button input information, and may include
identification information ID of the pen, of which the pen informs
the touch display device 100.
The touch driving circuit TDC may receive data DATA output from the
pen and applied to the touch panel TSP through one or more touch
electrodes TE.
Referring to FIG. 11, during the finger sensing interval F, a touch
driving signal TDS in the form of a modulation signal (also called
an AC signal or a pulse signal), the voltage level of which varies,
may be applied to all or some of the plurality of touch electrodes
TE disposed in the touch panel TSP.
Referring to FIG. 11, during the finger sensing interval F, when
there is a pen, a pen signal PENS may be output from the pen and be
applied to the touch panel TSP.
As described above, the touch display device 100 according to the
aspects of the present disclosure has a considerable difficulty in
sensing two or more pens for the reason of difficulty of
identification of the pens and lack of time assigned to the sensing
intervals because the plurality of touch intervals LHB 1 to LHB 16
in one frame period have to be assigned to various sensing
intervals F, B, P, T, and D.
In the following, an efficient multi-pen sensing method will be
described.
FIGS. 13 to 15 are views illustrating a time division driving
scheme for multi-pen sensing by a touch display device 100
according to aspects of the present disclosure.
Referring to FIG. 13, in order to sense the positions and the tilts
of two or more pens Pen #1, Pen #2, Pen #3, and Pen #4, the touch
display device 100 according to the aspects of the present
disclosure may be driven in a scheme in which one touch interval
(e.g., LHB 2, LHB 3, LHB9, LHB 5, LHB 13, and LHB 14) is
time-divided into two or more small invervals (e.g., P1, P3, T1,
T3, P2, P4, T2, and T4, hereinafter also called `time division
sensing intervals`), and two or more pens Pen #1, Pen #2, Pen #3,
and Pen #4 are assigned to the above time division sensing
intervals (e.g., P1, P3, T1, T3, P2, P4, T2, and T4),
respectively.
In order to sense data of two or more pens Pen #1, Pen #2, Pen #3,
and Pen #4, the touch display device 100 according to the aspects
of the present disclosure may sense data of a pen according to a
predetermined sequence during a data sensing interval D while not
time-dividing the data sensing interval D corresponding to one
touch interval.
In the following, for convenience of description, it will be
assumed that four pens Pen #1, Pen #2, Pen #3, and Pen #4 are
provided. Hereinafter, in the drawings, in `P(number)`, the number
corresponds to the number of a pen and P means a position sensing
interval. For example, P1 means a sensing interval (a touch
interval) for sensing the position of a first pen Pen #1, and P3
means a sensing interval (a touch interval) for sensing the
position of a third pen Pen #3. Similarly, in the drawings, in
`T(number)`, the number corresponds to the number of a pen and T
means a tilt sensing interval. For example, T1 means a sensing
interval (a touch interval) for sensing the tilt of a first pen Pen
#1, and T3 means a sensing interval (a touch interval) for sensing
the tilt of a third pen Pen #3. Similarly, in the drawings, in
`D(number)`, the number corresponds to the number of a pen and D
means a data sensing interval. For example, D1 means a sensing
interval (a touch interval) for sensing the data of a first pen Pen
#1, and D3 means a sensing interval (a touch interval) for sensing
the data of a third pen Pen #3.
Referring to FIGS. 13 and 14, it will be assumed that respective
identification information ID of four pens Pen #1, Pen #2, Pen #3,
and Pen #4 is 01, 02, 03, and 04. FIGS. 13 and 14 may correspond to
a case in which the first pen Pen #1, the second pen Pen #2, the
third pen Pen #3, and the fourth pen Pen #4 are sequentially
discovered.
The details will be described with reference to FIG. 14. The
assignment of the touch interval of FIG. 14 may be slightly
different from the assignment of the touch interval of FIG. 13.
However, the assignment of the touch intervals is simply
exemplary.
The operation period of the touch driving circuit TDC may include a
plurality of touch intervals LHB 1 to LHB 16.
The plurality of touch intervals LHB 1 to LHB 16 may include a
first position sensing interval P1,3 and a second position sensing
interval P2,4.
The first position sensing interval P1,3 may include a first time
division position sensing interval P1 and a third time division
position sensing interval P3. In the example of FIG. 14, the first
position sensing interval P1,3 corresponds to LHB 5 and LHB 13 in
the first and second frames, respectively.
The second position sensing interval P2,4 may include a second time
division sensing interval P2 and a fourth time division position
sensing interval P4. In the example of FIG. 14, the second position
sensing interval P2,4 corresponds to LHB 2 and LHB 9 in the first
and second frames, respectively.
During the first time division position sensing interval P1
obtained by time-dividing the first position sensing interval P1,3,
the touch driving circuit TDC may detect a pen signal PENS output
from the first pen Pen #1 through the touch panel TSP. The position
(location) of the first pen Pen #1 may be sensed from the detection
result.
During the second time division position sensing interval P2
obtained by time-dividing the second position sensing interval
P2,4, the touch driving circuit TDC may detect a pen signal output
from the second pen Pen #2, which is different from the first pen
Pen #1, through the touch panel TSP. The position (location) of the
second pen Pen #2 may be sensed from the detection result.
When the third pen PEN #3 is further discovered, during a third
time division position sensing interval P3 obtained by
time-dividing the first position sensing interval P1,3, the touch
driving circuit TDC may detect a pen signal PENS output from the
third pen Pen #3 through the touch panel TSP. The position
(location) of the third pen Pen #3 may be sensed from the detection
result.
When the fourth pen PEN #4 is further discovered, during a fourth
time division position sensing interval P4 obtained by
time-dividing the second position sensing interval P2,4, the touch
driving circuit TDC may detect a pen signal PENS output from the
fourth pen Pen #4 through the touch panel TSP. The position
(location) of the fourth pen Pen #4 may be sensed from the
detection result.
Referring to FIG. 14, the plurality of touch intervals LHB 1 to LHB
16 may include a first tilt sensing interval T1,3 and a second tilt
sensing interval T2,4.
The first tilt sensing interval T1,3 may include a first time
division tilt sensing interval T1 and a third time division tilt
sensing interval T3. In the example of FIG. 14, the first tilt
sensing interval T1,3 corresponds to LHB 14 in the first and second
frames, respectively.
The second tilt sensing interval T2,4 may include a second time
division tilt sensing interval T2 and a fourth time division tilt
sensing interval T4. In the example of FIG. 14, the second tilt
sensing interval T2,4 corresponds to LHB 3 in the first and second
frames, respectively.
During the first time division tilt sensing interval T1 obtained by
time-dividing the first tilt sensing interval T1,3, the touch
driving circuit TDC may detect a pen signal PENS output from the
first pen Pen #1 through the touch panel TSP. The tilt
(inclination) of the first pen Pen #1 may be sensed from the
detection result.
During the second time division tilt sensing interval T2 obtained
by time-dividing the second tilt sensing interval T2,4, the touch
driving circuit TDC may detect a pen signal PENS output from the
second pen Pen #2, which is different from the first pen Pen #1,
through the touch panel TSP. The tilt (inclination) of the second
pen Pen #2 may be sensed from the detection result.
When the third pen PEN #3 is further discovered, during a third
time division tilt sensing interval T3 obtained by time-dividing
the first tilt sensing interval T1,3, the touch driving circuit TDC
may detect a pen signal PENS output from the third pen Pen #3
through the touch panel TSP. The tilt (inclination) of the third
pen Pen #3 may be sensed from the detection result.
When the fourth pen PEN #4 is further discovered, during a fourth
time division tilt sensing interval T4 obtained by time-dividing
the second tilt sensing interval P2,4, the touch driving circuit
TDC may detect a pen signal PENS output from the fourth pen Pen #4
through the touch panel TSP. The tilt (inclination) of the fourth
pen Pen #4 may be sensed from the detection result.
Referring to FIGS. 14 and 15, the plurality of touch intervals LHB
1 to LHB 16 in a first frame period Frame #1 may further include a
first data sensing interval D1 and a second data sensing interval
D2. In the example of FIG. 14, the first data sensing interval D1
corresponds to LHB 6 and LHB 7 in the first frame period Frame #1.
The second data sensing interval D2 corresponds to LHB 10 and LHB
11 in the first frame period Frame #1.
Referring to FIGS. 14 and 15, the plurality of touch intervals LHB
1 to LHB 16 in a second frame period Frame #2 may further include a
third data sensing interval D3 and a fourth data sensing interval
D4. In the example of FIG. 14, the third data sensing interval D3
corresponds to LHB 6 and LHB 7 in the second frame period Frame #2.
The fourth data sensing interval D4 corresponds to LHB 10 and LHB
11 in the second frame period Frame #2.
During the first data sensing interval D1, the touch driving
circuit TDC detects data output from the first pen Pen #1 through
the touch panel TSP. Various pieces of additional information of
the first pen Pen #1 may be sensed from the detection result. The
data output from the first pen Pen #1 may include a pen ID of the
first pen Pen #1. The pen ID of the first pen Pen #1 may be a
unique ID of the first pen Pen #1 given to the first pen Pen #1 by
the pen manufacturer or may be a temporary ID temporarily assigned
(given) to the first pen Pen #1.
During the second data sensing interval D2, the touch driving
circuit TDC detects data output from the second pen Pen #2 through
the touch panel TSP. Various pieces of additional information of
the second pen Pen #2 may be sensed from the detection result. The
data output from the second pen Pen #2 may include a pen ID of the
second pen Pen #2. The pen ID of the second pen Pen #2 may be a
unique ID UID of the second pen Pen #2 given to the second pen Pen
#2 by the pen manufacturer or may be a temporary ID temporarily
assigned (given) to the second pen Pen #2.
When the third pen Pen #3 is further discovered, the touch driving
circuit TDC detects data output from the third pen Pen #3 through
the touch panel TSP during the third data sensing interval D3.
Various pieces of additional information of the third pen Pen #3
may be sensed from the detection result.
When the fourth pen Pen #4 is further discovered, the touch driving
circuit TDC detects data output from the fourth pen Pen #4 through
the touch panel TSP during the fourth data sensing interval D4.
Various pieces of additional information of the fourth pen Pen #4
may be sensed from the detection result.
Although position sensing interval(s), tilt sensing interval(s),
and data sensing interval(s) are included in one frame period in
FIG. 14, one or more of position sensing interval(s), tilt sensing
interval(s), and data sensing interval(s) may be included in one
frame period.
Referring to FIG. 14, the temporal lengths of the first to fourth
time division position sensing intervals P1, P2, P3, and P4 and the
temporal lengths of the first to fourth tilt position sensing
intervals T1, T2, T3, and T4 are the same.
The temporal lengths of the first to fourth time division position
sensing intervals P1, P2, P3, and P4 may be shorter than the
temporal lengths of the first to fourth data sensing intervals D1,
D2, D3, and D4. The temporal lengths of the first to fourth tilt
position sensing intervals T1, T2, t3, and T4 may be shorter than
the temporal lengths of the first to fourth data sensing intervals
D1, D2, D3, and D4.
Referring to FIG. 14, for example, the position for one pen are
sensed four times during two frame periods, the tilt for one pen is
sensed two times, and data (additional information) for one pen is
sensed one time.
Accordingly, for example, the ratio of the sensing speeds (or also
called a report rate) for the position, the sensing speed for the
tilt, and the sensing speed for the data may be 4:2:1. As an
example, the sensing speed (or also called a report rate) for the
position may be 120 Hz, the sensing speed for the tilt may be 60
Hz, and the sensing speed for the data may be 30 Hz.
During the first time division position sensing interval P1
obtained by time-dividing the first position sensing interval P1,3,
the touch driving circuit TDC may detect a signal through a first
touch electrode group (an aggregate of the touch electrodes TE
sensed during the first time division position sensing interval P1)
of the touch panel TSP. During the third time division position
sensing interval P3 obtained by time-dividing the first position
sensing interval P1,3, the touch driving circuit TDC may detect a
signal through a second touch electrode group (an aggregate of the
touch electrodes TE sensed during the third time division position
sensing interval P3) of the touch panel TSP. The first touch
electrode group and the second touch electrode group may be the
same or may be different.
During the second time division position sensing interval P2
obtained by time-dividing the second position sensing interval
P2,4, the touch driving circuit TDC may detect a signal through the
first touch electrode group (an aggregate of the touch electrodes
TE sensed during the second time division position sensing interval
P2) of the touch panel TSP. During the fourth time division
position sensing interval P4 obtained by time-dividing the second
position sensing interval P2,4, the touch driving circuit TDC may
detect a signal through the second touch electrode group (an
aggregate of the touch electrodes TE sensed during the fourth time
division position sensing interval P4) of the touch panel TSP. The
first touch electrode group and the second touch electrode group
may be the same or may be different.
FIGS. 16 to 20 are views illustrating a time
division/multi-frequency driving scheme for multi-pen sensing by a
touch display device 100 according to aspects of the present
disclosure.
Referring to FIG. 16, the touch display device 100 according to the
aspects of the present disclosure may be driven in a scheme in
which one touch interval (e.g., LHB 2, LHB 3, LHB9, LHB 5, LHB 13,
and LHB 14) is time-divided into two or more small intervals (e.g.,
P1, P3, T1, T3, P2, P4, T2, and T4, hereinafter also called `time
division sensing intervals`), and two or more pens Pen #1, Pen #2,
Pen #3, and Pen #4 are assigned to the above time division sensing
intervals (e.g., P1, P3, T1, T3, P2, P4, T2, and T4),
respectively.
In order to sense data of two or more pens Pen #1, Pen #2, Pen #3,
and Pen #4, the touch display device 100 according to the aspects
of the present disclosure may sense data of a pen according to a
predetermined sequence during a data sensing interval D while not
time-dividing the data sensing interval D corresponding to one
touch interval.
Referring to FIG. 16, the plurality of pens Pen #1, Pen #2, Pen #3,
Pen #4, . . . may output a pen signal PENS and data DATA having,
among two or more usable signal frequencies SF, assigned signal
frequencies F1 and F2.
The touch driving circuit TDC may detect data at the operation
frequencies OF assigned during the touch intervals LHB 10, LHB 11,
LHB 6, and LHB 7 corresponding to the data sensing intervals D1,
D2, D3, and D4.
However, the touch driving circuit TDC does not detect data at one
operation frequency OF assigned during the position sensing
interval and the tilt sensing intervals.
The touch driving circuit TDC may detect a signal for sensing the
position at the operation frequencies OF assigned during the first
and third time division position sensing intervals P1 and P3
obtained by time-dividing the first position sensing interval P1,3.
The touch driving circuit TDC may detect a signal for sensing the
position at the operation frequencies OF assigned during the second
and fourth time division position sensing intervals P2 and P4
obtained by time-dividing the second position sensing interval
P2,4.
The touch driving circuit TDC may detect a signal for sensing the
position at the operation frequencies OF assigned during the first
and third time division tilt sensing intervals T1 and T3 obtained
by time-dividing the first tilt sensing interval P1,3. The touch
driving circuit TDC may detect a signal for sensing the position at
the operation frequencies OF assigned during the second and fourth
time division tilt sensing intervals T2 and T4 obtained by
time-dividing the second tilt sensing interval P2,4.
The details will be described with reference to FIGS. 17 to 19.
Referring to FIG. 17, the first pen Pen #1 and the second pen Pen
#2 output a pen signal PENS and data DATA by using a first signal
frequency F1 as a signal frequency SF.
Referring to FIG. 17, the third pen Pen #3 and the fourth pen Pen
#4 output a pen signal PENS and data DATA by using a second signal
frequency F2 as a signal frequency SF. The second signal frequency
F2 is a frequency that is different from the first signal frequency
F1.
The touch driving circuit TDC detects a signal according to a
timing of one of the first operation frequency F1 and the second
operation frequency F2 as the operation frequency OF.
The first signal frequency F1 is the same as the first operation
frequency F1. The second signal frequency F2 is the same as the
second operation frequency F2.
The touch driving circuit TDC may detect a pen signal PENS having
the same signal frequency SF as the operation frequency OF.
The pen signal PENS having a signal frequency SF that is different
from the operation frequency OF of the touch driving circuit TDC
may not be received by the touch driving circuit TDC or may not
normally detected by the touch driving circuit TDC even though it
is received by the touch driving circuit TDC.
Referring to FIGS. 17 and 18, the touch driving circuit TDC detects
a signal at the first operation frequency F1 during the first time
division position sensing interval P1 obtained by time-dividing the
first position sensing interval P1,3, and detects a signal at the
second operation frequency F2 that is different from the first
operation frequency F1 during the third time division position
sensing interval P3 obtained by time-dividing the first position
sensing interval P1,3.
During the first position sensing interval P1,3, the first pen Pen
#1 outputs a pen signal PENS having the first signal frequency F1,
and the third pen Pen #3 outputs a pen signal PENS having the
second signal frequency F2.
Because the touch driving circuit TDC may detect a pen signal PENS
having the same signal frequency SF as the operation frequency OF,
it may detect a pen signal PENS output from the first pen Pen #1
and having the first signal frequency F1 through the touch panel
TSP during the first time division position sensing interval P1,
and may detect a pen signal PENS output from the third pen Pen #3
and having the second signal frequency F2 through the touch panel
TSP during the third time division position sensing interval
P3.
Referring to FIGS. 17 and 18, the touch driving circuit TDC detects
a signal at the first operation frequency F1 during the second time
division position sensing interval P2 obtained by time-dividing the
second position sensing interval P2,4, and detects a signal at the
second operation frequency F2 during the fourth time division
position sensing interval P4 obtained by time-dividing the second
position sensing interval P2,4.
During the second position sensing interval P2,4, the second pen
Pen #2 outputs a pen signal PENS having the first signal frequency
F1, and the fourth pen Pen #4 outputs a pen signal PENS having the
second signal frequency F2.
Because the touch driving circuit TDC may detect a pen signal PENS
having the same signal frequency SF as the operation frequency OF,
it may detect a pen signal PENS output from the second pen Pen #2
and having the first signal frequency F1 through the touch panel
TSP during the second time division position sensing interval P2,
and may detect a pen signal PENS output from the fourth pen Pen #4
and having the second signal frequency F2 through the touch panel
TSP during the fourth time division position sensing interval
P4.
Referring to FIGS. 17 and 18, the touch driving circuit TDC detects
a signal at the first operation frequency F1 during the first time
division tilt sensing interval T1 obtained by time-dividing the
first tilt sensing interval T1,3, and detects a signal at the
second operation frequency F2 that is different from the first
operation frequency F1 during the third time division tilt sensing
interval T3 obtained by time-dividing the first tilt sensing
interval T1,3.
During the first tilt sensing interval T1,3, the first pen Pen #1
outputs a pen signal PENS having the first signal frequency F1, and
the third pen Pen #3 outputs a pen signal PENS having the second
signal frequency F2.
Because the touch driving circuit TDC may detect a pen signal PENS
having the same signal frequency SF as the operation frequency OF,
it may detect a pen signal PENS output from the first pen Pen #1
and having the first signal frequency F1 through the touch panel
TSP during the first time division tilt sensing interval T1, and
may detect a pen signal PENS output from the third pen Pen #3 and
having the second signal frequency F2 through the touch panel TSP
during the third time division tilt sensing interval T3.
Referring to FIGS. 17 and 18, the touch driving circuit TDC detects
a signal at the first operation frequency F1 during the second time
division tilt sensing interval T2 obtained by time-dividing the
second tilt sensing interval T2,4, and detects a signal at the
second operation frequency F2 during the fourth time division tilt
sensing interval T4 obtained by time-dividing the second tilt
sensing interval T2,4.
During the second tilt sensing interval T2,4, the second pen Pen #2
outputs a pen signal PENS having the first signal frequency F1, and
the fourth pen Pen #4 outputs a pen signal PENS having the second
signal frequency F2.
Because the touch driving circuit TDC may detect a pen signal PENS
having the same signal frequency SF as the operation frequency OF,
it may detect a pen signal PENS output from the second pen Pen #2
and having the first signal frequency F1 through the touch panel
TSP during the second time division tilt sensing interval T2, and
may detect a pen signal PENS output from the fourth pen Pen #4 and
having the second signal frequency F2 through the touch panel TSP
during the fourth time division tilt sensing interval T4.
As described above, during the position and tilt sensing, the touch
driving circuit TDC detects a signal while changing the operation
frequencies in the first frame period Frame #1 and the second frame
period Frame #2, respectively.
However, the touch driving circuit TDC performs an operation of
detecting a signal at the first operation frequency F1 during the
first frame period Frame #1 and performs an operation of detecting
a signal at the second operation frequency F2 during the second
frame period Frame #2.
Referring to FIGS. 17, 19, and 20, the touch driving circuit TDC
detects data at the first operation frequency F1 during a first
data sensing interval D1 corresponding to LHB 6 and LHB 7 in the
first frame period Frame #1, and detects data DATA output from the
first pen Pen #1 and having the first signal frequency F1 that is
the same as the first operation frequency F1, through the touch
panel TSP.
However, because the touch driving circuit TDC detects data at the
first operation frequency F1 during a first data sensing interval
D1 corresponding to LHB 6 and LHB 7 in the first frame period Frame
#1, and does not detect data DATA output from the second pen Pen #2
and having the second signal frequency F1 that is different from
the first operation frequency F1, through the touch panel TSP.
Referring to FIGS. 17, 19, and 20, the touch driving circuit TDC
detects data at the first operation frequency F1 during a second
data sensing interval D2 corresponding to LHB 10 and LHB 11 in the
first frame period Frame #1, and detects data DATA output from the
second pen Pen #1 and having the first signal frequency F1 that is
the same as the first operation frequency F1, through the touch
panel TSP.
However, because the touch driving circuit TDC detects data at the
first operation frequency F1 during a second data sensing interval
D2 corresponding to LHB 10 and LHB 11 in the first frame period
Frame #1, and does not detect data DATA output from the fourth pen
Pen #4 and having the second signal frequency F2 that is different
from the first operation frequency F1, through the touch panel
TSP.
Referring to FIGS. 17, 19, and 20, the touch driving circuit TDC
detects data at the second operation frequency F2 during a third
data sensing interval D3 corresponding to LHB 6 and LHB 7 in the
second frame period Frame #2, and detects data DATA output from the
third pen Pen #3 and having the second signal frequency F2 that is
the same as the second operation frequency F2, through the touch
panel TSP.
However, because the touch driving circuit TDC detects data at the
second operation frequency F2 during a third data sensing interval
D3 corresponding to LHB 6 and LHB 7 in the second frame period
Frame #2, and does not detect data DATA output from the first pen
Pen #1 and having the first signal frequency F1 that is different
from the second operation frequency F2, through the touch panel
TSP.
Referring to FIGS. 17, 19, and 20, the touch driving circuit TDC
may detect data at the second operation frequency F2 during a
fourth data sensing interval D4 corresponding to LHB 10 and LHB 11
in the second frame period Frame #2, and may detect data DATA
output from the fourth pen Pen #4 and having the second signal
frequency F2 that is the same as the second operation frequency F2,
through the touch panel TSP.
However, because the touch driving circuit TDC detects data at the
second operation frequency F2 during a fourth data sensing interval
D4 corresponding to LHB 10 and LHB 11 in the second frame period
Frame #2, and does not detect data DATA output from the second pen
Pen #2 and having the first signal frequency F1 that is different
from the second operation frequency F2, through the touch panel
TSP.
Although position sensing interval(s), tilt sensing interval(s),
and data sensing interval(s) are included in one frame period in
FIG. 17, one or more of position sensing interval(s), tilt sensing
interval(s), and data sensing interval(s) may be included in one
frame period.
The touch display device 100 according to the aspects of the
present disclosure may include a touch panel TSP which, in order to
provide multi-pen sensing based on frequency, includes a plurality
of touch electrodes TE and receives a pen signal output from two or
more pens, and a touch driving circuit TDC which detects a pen
signal output from two or more pens Pen #1, Pen #2, . . . by
sensing one or more of the plurality of touch electrodes TE.
The pen signal output from the two or more pens Pen #1, Pen #2, . .
. may have different signals.
The touch driving circuit TDC may detect a signal by sequentially
operating at two or more operation frequencies OF, and may detect a
pen signal having the same signal frequency SF as each operation
frequency OF.
FIG. 21 is a view illustrating multiplexing driving schemes of a
touch display device 100 according to aspects of the present
disclosure.
As described above with reference to FIGS. 13 to 20, when the first
position sensing interval P1,3 corresponding to one touch interval
LHB is divided into first and second time division position sensing
intervals P1 and P3, the touch driving circuit TDC may detect a
signal through a first touch electrode group MUX_GR #1 of the touch
panel TSP during the first time division position sensing interval
P1, and may detect a signal through a second touch electrode group
MUX_GR #2 of the touch panel TSP during the third time division
position sensing interval P3.
As described above with reference to FIGS. 13 to 20, when the
second position sensing interval P2,4 corresponding to one touch
interval LHB is divided into second and fourth time division
position sensing intervals P2 and P4, the touch driving circuit TDC
may detect a signal through the first touch electrode group MUX_GR
#1 of the touch panel TSP during the second time division position
sensing interval P2, and may detect a signal through the second
touch electrode group MUX_GR #2 of the touch panel TSP during the
fourth time division position sensing interval P4.
The first touch electrode group MUX_GR #1 is a group of touch
electrodes TE that may be simultaneously sensed by the plurality of
sensing units SU. The second touch electrode group MUX_GR #2 is a
group of touch electrodes TE that may be simultaneously sensed by
the plurality of sensing units SU. The first touch electrode group
MUX_GR #1 and the second touch electrode group MUX_GR #2 are sensed
at different timings.
As in cases 1 and 2 of FIG. 21, the touch electrodes TE included in
the first touch electrode group MUX_GR #1 and the touch electrodes
TE included in the second touch electrode group MUX_GR #2 may be
located in different areas of the touch panel TSP.
As in case 3 of FIG. 21, the touch electrodes TE included in the
first touch electrode group MUX_GR #1 and the touch electrodes TE
included in the second touch electrode group MUX_GR #2 may be
located in the same of the touch panel TSP.
Accordingly, the touch display device 100 may increase the report
rate by repeatedly sensing the same area of the touch panel TSP two
times.
FIG. 22 is a view illustrating fast pairing of a touch display
device 100 according to aspects of the present disclosure.
Referring to FIG. 22, if an input of a pen is made in a pen
searching process, the touch display device 100 requests a unique
ID UID of the pen from the pen and receives the unique ID UID. The
unique ID UID of the pen is unique identification information given
to the pen by the pen manufacturer, and is identification
information that helps identify the pen even in a state in which
the pen does not communicate with the touch display device 100.
The touch display device 100 assigns a temporary ID of the pen that
is to be used in a communication process for the pen sensing if
receiving the unique ID UID of the pen. The temporary ID assigned
to the pen by the touch display device 100 is temporary
identification information that is available only in a state in
which the pen communicates with the touch display device 100. The
bit unit of the temporary ID of the pen may be smaller than the bit
unit of the unique ID UID of the pen.
For the above-described multi-pen sensing, the touch display device
100 may assign a signal frequency SF that is to be used by the pen
if receiving the unique ID UID of the pen.
The touch display device 100 may inform the pen of information on
the temporary ID assigned to the pen and the signal frequency SF,
through a beacon signal BCON. The process is called pairing between
the touch display device 100 and the pen.
In the data sensing interval, the pen may transmit the temporary ID
or information corresponding to the temporary ID to the touch
display device 100 while containing the temporary ID or the
corresponding information in the data DATA. Accordingly, during the
communication, fast pairing may be provided.
FIG. 23 is a view illustrating a driving method for enhancing a
touch/pen report rate of a touch display device 100 according to
aspects of the present disclosure.
Referring to FIG. 23, the touch driving circuit TDC may perform a
signal detecting operation according to a touch synchronization
signal Tsync in which a first voltage level interval LV1 and a
second voltage level interval LV2 are repeated.
For example, the first voltage level interval LV1 may be a low
level voltage interval, and the second voltage level interval LV2
may be a high level voltage interval. To the contrary, the first
voltage level interval LV1 may be a high level voltage interval,
and the second voltage level interval LV2 may be a low level
voltage interval.
Referring to FIG. 23, the touch controller TCTR may generate a
touch synchronization signal Tsync in which the first voltage level
interval LV1 and the second voltage level interval LV2 are repeated
and supply the touch synchronization signal Tsync to the touch
driving circuit TDC, based on a reference touch synchronization
signal Tsync_REF in which a first state interval ST1 that defines a
touch interval and a second state interval ST2 that defines a
non-touch interval are repeated.
The first state interval ST1 may be a low level voltage interval,
and the second state interval ST2 may be a high level voltage
interval. To the contrary, the first state interval ST1 may be a
high level voltage interval, and the second state interval ST2 may
be a low level voltage interval.
One first state interval ST1 of the reference touch synchronization
signal Tsync_REF may correspond to two or more first voltage level
intervals LV1 and one or more second voltage level intervals
VL2.
One of the two or more first voltage level intervals LV1 may
include a first time division position sensing interval P1 and a
third time division position sensing interval P2, and the other may
include a second time division position sensing interval P2 and a
fourth time division position sensing interval P4.
One of the two or more first voltage level intervals LV1 may
include a first time division tilt sensing interval T1 and a third
time division tilt sensing interval T2, and the other may include a
second time division tilt sensing interval T2 and a fourth time
division tilt sensing interval T4.
For example, as illustrated in FIG. 23, one first state interval
ST1 of the reference touch synchronization signal Tsync_REF may
correspond to two first voltage level intervals LV1 and one second
voltage level interval VL2.
The touch driving circuit TDC may sense the first touch electrode
group MUX_GR #1 and the second touch electrode group MUX_GR #2
during the two first voltage level intervals LV1.
The touch controller TCTR may supply a pulse width modulation
signal PWM_TDC to the touch driving circuit TDC. The pulse width
modulation signal PWM_TPIC may be used as a touch driving signal
TDS.
The touch power circuit TPIC may generate a load free driving
signal LFDS based on the pulse width modulation signal PWM_TPIC
received from the touch controller TCTR and the reference touch
synchronization signal Tsync_REF received from the display
controller DCTR, and may supply the load free driving signal LFDS
to the touch driving circuit TDC.
If the touch driving circuit TDC drives the touch panel TSP by
using the reference touch synchronization signal Tsync_REF in which
the first state interval ST1 that defines a touch interval and the
second state interval ST2 that defines a non-touch interval are
repeated, the touch driving circuit TDC may sense the first touch
electrode group MUX_GR #1 and the second touch electrode group
MUX_GR #2 during the first state interval ST1.
However, if the touch driving circuit TDC drives the touch panel
TSP by using a touch synchronization signal Tsync newly generated
based on the reference touch synchronization signal Tsync_REF, the
touch driving circuit TDC may sense the first touch electrode group
MUX_GR #1 and the seconds touch electrode group MUX_GR #2 two times
during the first state interval ST1. Accordingly, the touch and pen
report rate may be increased.
FIG. 24 is a view illustrating an issue of losing position of a pen
when the pen is sensed by a touch display device 100 according to
aspects of the present disclosure.
Referring to FIG. 24, when the pen rapidly contacts the touch panel
TSP as the search rate, at which it may be determined whether an
input by the pen or the finger is made, is restrictive to a
predetermined speed (e.g., 60 Hz), some pen positions may be lost
as the input of the pen is slowly responsive due to a search
latency and the like.
In the following, a prompt search providing method for solving the
pen position loss issue will be described.
FIG. 25 is a view illustrating the degrees of transition for
operation modes of a touch display device 100 according to aspects
of the present disclosure. FIG. 26 is a flowchart illustrating
transition methods for operation modes of a touch display device
100 according to aspects of the present disclosure.
Referring to FIG. 25, the operation modes of the touch display
device 100 may include a search mode that is a default mode and
operates when there is no touch input by a finger or a pen, a pen
ID mode for receiving a pen ID UID when a touch input by a pen is
made, a pen mode for sensing one or more of the position, the tilt,
and data of the pen if the pen ID is received, and a finger mode
for sensing a touch by the finger when a touch input by the finger
is made.
The driving timing diagrams of FIGS. 14 and 17 are driving timing
diagrams when the touch driving circuit TDC is in the pen mode.
Referring to FIG. 26, the touch display device 100 is driven in the
search mode when there is no touch input by a finger and a pen
(S110).
The touch display device 100 determines whether a pen touch input
and a finger touch input are made while being driven in the search
mode (S112, S114), is driven in the pen ID mode if it is determined
in the determination result that a pen touch input is made (S120),
and is driven in the finger mode if a finger touch input is made
(S140).
The touch display device 100 is driven in the pen ID mode to
determine whether the unique ID UID of the pen is received from the
pen (S122).
The touch display device 100 is driven in the pen mode if the
unique ID (UID) of the pen is received from the pen (S130).
The touch display device 100 determines whether a pen touch input
is continuously made during the driving of the pen mode (S132), and
if the pen touch input is continuously made, the pen mode is
continuously driven (S130).
The touch display device 100 determines whether a pen touch input
is continuously made during the driving of the pen mode (S132), and
if the pen touch input is not made any more, it is determined
whether a finger touch input is made (S134).
The touch display device 100 drives the search mode again (S110) if
it is determined in the determination result of operation S134 that
there is no finger touch input.
The touch display device 100 drives the finger mode again (S140) if
it is determined in the determination result of operation S134 that
there is a finger touch input.
The touch display device 100 determines whether a pen touch input
is made during the finger mode driving (S140) (S142), and drives
the pen ID mode if there is not pen touch input in the
determination result of operation S142 (S120).
The touch display device 100 determines whether there is a finger
touch input (S144) if there is not pen touch input in the
determination result of operation S142, continuously drives the
finger mode (S140) if a finger touch input is continuously made,
and drives the search mode again (S110) if the finger touch input
disappears.
FIG. 27 is a diagram of driving timings for operation modes of a
touch display device 100 according to aspects of the present
disclosure.
Referring to FIG. 27, during the search mode, K touch intervals LHB
1 to LHB 16 in one frame period may include one or more beacon
transmission intervals B, n or more finger sensing intervals F, and
m pen position sensing intervals P (n.gtoreq.1, m.gtoreq.1, and
K.gtoreq.3).
During n or more finger sensing intervals F in the search mode, a
touch driving signal TDS, the voltage level of which swings, may be
applied to the plurality of touch electrodes TE during m pen
position sensing intervals P, a DC voltage may be applied to the
plurality of touch electrodes TE.
During the search mode, due to the characteristics of the pen
sensing, the number m of the pen position sensing intervals P is
larger than the number of the beacon transmission intervals B, and
also is larger than the number n of the finger sensing intervals
F.
Referring to FIG. 27, during the finger mode, K touch intervals LHB
1 to LHB 16 in one frame period may include one or more beacon
transmission intervals B, n or more finger sensing intervals F, and
m pen position sensing intervals P (n.gtoreq.1, m.gtoreq.1, and
K.gtoreq.3).
During the finger mode, the number n of the finger sensing
intervals F is larger than the number m of the pen position sensing
intervals P and is larger than the number of the beacon
transmission intervals B.
Referring to FIG. 27, during the pen mode, K touch intervals LHB 1
to LHB 16 in one frame period may include one or more beacon
transmission interval B, one or more finger sensing interval F, one
or more pen position sensing interval P, one or more pen tilt
sensing interval T, and one or more pen data sensing interval
D.
The number of the pen data sensing intervals D may vary according
to the kind and the amount of the information included in the
data.
Referring to FIG. 27, during the pen mode, K touch intervals LHB 1
to LHB 16 in one frame period may include one or more beacon
transmission interval B, one or more finger sensing interval F, one
or more pen position sensing interval P, one or more pen tilt
sensing interval T, and one or more pen data sensing interval D.
During the pen ID mode, the number of the pen data sensing
intervals D is largest.
FIG. 28 is a view illustrating a sensitivity decreasing issue when
a pen is sensed by a touch display device 100 according to aspects
of the present disclosure.
Referring to FIG. 28, if receiving pen pulses, the touch driving
circuit TDC detects symbols (Symbol #1, Symbol #2, Symbol #3, and
Symbol #4) expressed by pen pulses to sense the pen position and
the pen data, based on internal operation timings.
Referring to FIG. 28, the pen drives several symbols Symbol #1 to
Symbol #4 during one touch interval LHB in a phase shift key (PSK)
scheme. Through this, the touch display device 100 detects the
position and data DATA of the pen.
According to the example of FIG. 28, when the first symbol Symbol
#1 is changed to the second symbol Symbol #2, the phase of the pen
pulse is changed. When the second symbol Symbol #2 is changed to
the third symbol Symbol #3, the phase of the pen pulse is changed.
When the third symbol Symbol #3 is changed to the fourth symbol
Symbol #4, the phase of the pen pulse is not changed.
When the phase of the pen pulse is changed, the number of toggles
of the pen pulse decreases as compared with when there is no phase
change.
Accordingly, when there is a phase change of the pen pulse, the
intensity of the pen touch sensitivity detected by the touch
display device 100 decreases as compared with when there is not
phase change. Referring to FIG. 28, the sensitivities (-90, +90) of
the first symbol Symbol #1 and the second symbol Symbol #2 are
lower than the sensitivities (-100, -100) of the third symbol
Symbol #3 and the fourth symbol Symbol #4.
In particular, the change of the detection sensitivity generated by
the phase change of the pen pulse may generate distortion of the
position of the pen. Referring to FIG. 28, the deviation between
the sensitivity (-90) of the first symbol Symbol #1 for the
position sensing and the sensitivity (-100) of the third symbol
Symbol #3 may greatly influence the pen position.
FIG. 29 is a view illustrating a sensitivity enhancing method when
a pen is sensed by a touch display device 100 according to aspects
of the present disclosure.
Referring to FIG. 29, in order to remove a change of the touch
sensitivity by the phase change of the pen pulse, the touch display
device 100 does not detect a touch at a time point at which a
symbol changes.
The touch display device 100 secures the maximum sensitivity by
touch detecting all pulses in the case of detection of pen data
that does not require position detection.
Referring to FIG. 29, each touch interval LHB includes three or
more division intervals PT1, PT2, PT3, and PT4. In each of the
three or more division intervals PT1, PT2, PT3, and PT4, a pen
signal (pen pulse) including a plurality of pulses is applied to
one or more touch electrodes TE.
For example, the three or more division intervals PT1, PT2, PT3,
and PT4 may be time division sensing intervals obtained by
time-dividing the touch interval LHB for multi-pen sensing.
A plurality of pulses included in a pen signal in each of the three
or more division intervals PT1, PT2, PT3, and PT4 express one
symbol. For example, the pen pulses in the first division interval
PT1 express the first symbol Symbol #1. The pen pulses in the
second division interval PT2 express the second symbol Symbol #2.
The pen pulses in the third division interval PT3 express the third
symbol Symbol #3. The pen pulses in the fourth division interval
PT4 express the fourth symbol Symbol #4.
The touch driving circuit TDC may detect a signal based on the pen
pulses during a time period, except for a symbol change time point
related to the pen position sensing.
For example, referring to FIG. 29, when the first symbol Symbol #1
related to the position sensing is changed to the second symbol
Symbol #2, the phase of the pen pulse changes. When the second
symbol Symbol #2 is changed to the third symbol Symbol #3, the
phase of the pen pulse is changed. When the third symbol Symbol #3
related to the position sensing is changed to the fourth symbol
Symbol #4, the phase of the pen pulse is not changed.
The touch driving circuit TDC does not detect a signal for the
final pulse part corresponding to the first symbol Symbol #1
related to the position sensing. The touch driving circuit TDC does
not detect a signal for the final pulse part corresponding to the
third symbol Symbol #3 related to the position sensing.
According to the above description, the deviation between the
sensitivity (-90) of the first symbol Symbol #1 for the position
sensing and the sensitivity (-90) of the third symbol Symbol #3 may
be removed to prevent a distortion for the pen position.
FIGS. 30 and 31 are views illustrating a control method for
enhancing sensitivity when a pen is sensed by a touch display
device 100 according to aspects of the present disclosure.
According to the example of FIG. 29, the touch driving circuit TDC
does not detect a signal for the final pulse parts corresponding to
the first symbol Symbol #1 related to the position sensing and the
third symbol Symbol #3.
To achieve this, as illustrated in FIG. 30, the switch controller
SW_CTR may turn off a switch SW that controls connection between
the corresponding touch electrode TE and the sensing unit SU in
advance before a predetermined turn-off time point at a time point
at which the first symbol Symbol #1 corresponding to the first
division interval PT1 is changed. The switch controller SW_CTR may
turn off a switch SW that controls connection between the
corresponding touch electrode TE and the sensing unit SU in advance
before a predetermined turn-off time point at a time point at which
the third symbol Symbol #3 corresponding to the third division
interval PT3 is changed.
The above-mentioned switch SW may be a switch included in the first
multiplexer circuit MUX1 of FIG. 4.
For a scheme that is different from the scheme of FIG. 30, the
touch driving circuit TDC may include a switch SW connected between
an input terminal and an output terminal of the integrator INTG
included in each sensing unit SU.
The switch controller SW_CTR may control an on/off operation of the
switch SW.
The switch controller SW_CTR may turn off a switch SW that controls
connection between the corresponding touch electrode TE and the
sensing unit SU in advance before a predetermined turn-off time
point at a time point at which the first symbol Symbol #1
corresponding to the first division interval PT1 is changed. The
switch controller SW_CTR may turn off a switch SW that controls
connection between the corresponding touch electrode TE and the
sensing unit SU in advance before a predetermined turn-off time
point at a time point at which the third symbol Symbol #3
corresponding to the third division interval PT3 is changed.
According to the above-described aspects of the present disclosure,
a touch display device 100 that may effectively sense a larger
number of pens and a touch sensing circuit may be provided.
According to the aspects of the present disclosure, a touch display
device 100 that performs multiplexing, by which sensing speed may
be increased, and a touch sensing circuit may be provided.
According to the aspects of the present disclosure, a touch display
device 100 that performs multiplexing, by which pen search speed
may be increased, and a touch sensing circuit may be provided.
According to the aspects of the present disclosure, a touch display
device 100 that performs multiplexing, by which distortion of the
position of a pen may be prevented, and a touch sensing circuit may
be provided.
The above description and the accompanying drawings provide an
example of the technical idea of the present disclosure for
illustrative purposes only. Those having ordinary knowledge in the
technical field, to which the present disclosure pertains, will
appreciate that various modifications and changes in form, such as
combination, separation, substitution, and change of a
configuration, are possible without departing from the essential
features of the present disclosure. Therefore, the aspects
disclosed in the present disclosure are intended to illustrate the
scope of the technical idea of the present disclosure, and the
scope of the present disclosure is not limited by the aspect. The
scope of the present disclosure shall be construed on the basis of
the accompanying claims in such a manner that all of the technical
ideas included within the scope equivalent to the claims belong to
the present disclosure.
* * * * *